diff --git a/backend/backtest.py b/backend/backtest.py
index 37b4578..6de44b3 100644
--- a/backend/backtest.py
+++ b/backend/backtest.py
@@ -35,7 +35,7 @@ logging.basicConfig(
 )
 logger = logging.getLogger("backtest")
 
-PG_HOST = os.getenv("PG_HOST", "10.106.0.3")
+PG_HOST = os.getenv("PG_HOST", "127.0.0.1")
 PG_PORT = int(os.getenv("PG_PORT", "5432"))
 PG_DB = os.getenv("PG_DB", "arb_engine")
 PG_USER = os.getenv("PG_USER", "arb")
diff --git a/backend/db.py b/backend/db.py
index fc845dd..dd46397 100644
--- a/backend/db.py
+++ b/backend/db.py
@@ -1,6 +1,6 @@
 """
 db.py — PostgreSQL 数据库连接层
-统一连接到 Cloud SQL（PG_HOST 默认 10.106.0.3）
+统一连接到 Cloud SQL（PG_HOST 默认 127.0.0.1）
 同步连接池（psycopg2）供脚本类使用
 异步连接池（asyncpg）供FastAPI使用
 """
@@ -13,7 +13,7 @@ import psycopg2.pool
 from contextlib import contextmanager
 
 # PG连接参数（统一连接 Cloud SQL）
-PG_HOST = os.getenv("PG_HOST", "10.106.0.3")
+PG_HOST = os.getenv("PG_HOST", "127.0.0.1")
 PG_PORT = int(os.getenv("PG_PORT", 5432))
 PG_DB = os.getenv("PG_DB", "arb_engine")
 PG_USER = os.getenv("PG_USER", "arb")
diff --git a/backend/ecosystem.dev.config.js b/backend/ecosystem.dev.config.js
index 26a0623..e3e7703 100644
--- a/backend/ecosystem.dev.config.js
+++ b/backend/ecosystem.dev.config.js
@@ -5,8 +5,8 @@ module.exports = {
     interpreter: "python3",
     cwd: "/root/Projects/arbitrage-engine/backend",
     env: {
-      PG_HOST: "34.85.117.248",
-      CLOUD_PG_HOST: "34.85.117.248",
+      PG_HOST: "127.0.0.1",
+      CLOUD_PG_HOST: "127.0.0.1",
       CLOUD_PG_ENABLED: "true"
     }
   }]
diff --git a/backend/live_executor.py b/backend/live_executor.py
index 795a281..fb7b29d 100644
--- a/backend/live_executor.py
+++ b/backend/live_executor.py
@@ -49,7 +49,7 @@ if not _DB_PASSWORD:
     sys.exit(1)
 
 DB_CONFIG = {
-    "host": os.getenv("DB_HOST", "10.106.0.3"),
+    "host": os.getenv("DB_HOST", "127.0.0.1"),
     "port": int(os.getenv("DB_PORT", "5432")),
     "dbname": os.getenv("DB_NAME", "arb_engine"),
     "user": os.getenv("DB_USER", "arb"),
diff --git a/backend/market_data_collector.py b/backend/market_data_collector.py
index ccd5940..e0cc3b5 100644
--- a/backend/market_data_collector.py
+++ b/backend/market_data_collector.py
@@ -12,7 +12,7 @@ from psycopg2.extras import Json
 SYMBOLS = ["BTCUSDT", "ETHUSDT", "XRPUSDT", "SOLUSDT"]
 INTERVAL_SECONDS = 300
 
-PG_HOST = os.getenv("PG_HOST", "10.106.0.3")
+PG_HOST = os.getenv("PG_HOST", "127.0.0.1")
 PG_PORT = int(os.getenv("PG_PORT", "5432"))
 PG_DB = os.getenv("PG_DB", "arb_engine")
 PG_USER = os.getenv("PG_USER", "arb")
diff --git a/backend/migrate_v54.py b/backend/migrate_v54.py
index 8e8abac..64ed46c 100644
--- a/backend/migrate_v54.py
+++ b/backend/migrate_v54.py
@@ -12,7 +12,7 @@ import sys
 import psycopg2
 from psycopg2.extras import execute_values
 
-PG_HOST = os.environ.get("PG_HOST", "10.106.0.3")
+PG_HOST = os.environ.get("PG_HOST", "127.0.0.1")
 PG_PASS = os.environ.get("PG_PASS", "arb_engine_2026")
 PG_USER = "arb"
 PG_DB = "arb_engine"
diff --git a/backend/migrate_v54b_gates.py b/backend/migrate_v54b_gates.py
index b7a4ea1..d44dd4b 100644
--- a/backend/migrate_v54b_gates.py
+++ b/backend/migrate_v54b_gates.py
@@ -22,7 +22,7 @@ import os, sys
 import psycopg2
 from psycopg2.extras import RealDictCursor
 
-PG_HOST = os.getenv("PG_HOST", "10.106.0.3")
+PG_HOST = os.getenv("PG_HOST", "127.0.0.1")
 PG_USER = os.getenv("PG_USER", "arb")
 PG_PASS = os.getenv("PG_PASS", "arb_engine_2026")
 PG_DB   = os.getenv("PG_DB", "arb_engine")
diff --git a/backend/position_sync.py b/backend/position_sync.py
index 340c705..5a06845 100644
--- a/backend/position_sync.py
+++ b/backend/position_sync.py
@@ -40,7 +40,7 @@ if not _DB_PASSWORD:
     sys.exit(1)
 
 DB_CONFIG = {
-    "host": os.getenv("DB_HOST", "10.106.0.3"),
+    "host": os.getenv("DB_HOST", "127.0.0.1"),
     "port": int(os.getenv("DB_PORT", "5432")),
     "dbname": os.getenv("DB_NAME", "arb_engine"),
     "user": os.getenv("DB_USER", "arb"),
diff --git a/backend/risk_guard.py b/backend/risk_guard.py
index 62c40d7..6f41d1f 100644
--- a/backend/risk_guard.py
+++ b/backend/risk_guard.py
@@ -47,7 +47,7 @@ if not _DB_PASSWORD:
     sys.exit(1)
 
 DB_CONFIG = {
-    "host": os.getenv("DB_HOST", "10.106.0.3"),
+    "host": os.getenv("DB_HOST", "127.0.0.1"),
     "port": int(os.getenv("DB_PORT", "5432")),
     "dbname": os.getenv("DB_NAME", "arb_engine"),
     "user": os.getenv("DB_USER", "arb"),
diff --git a/scripts/replay_paper_trades.py b/scripts/replay_paper_trades.py
index 410d177..a815c7c 100644
--- a/scripts/replay_paper_trades.py
+++ b/scripts/replay_paper_trades.py
@@ -239,7 +239,7 @@ def replay_trade(cur, tid, symbol, direction, strategy, entry_ts, atr):
 
 
 def main(dry_run=False):
-    conn = psycopg2.connect(host='10.106.0.3', dbname='arb_engine', user='arb', password='arb_engine_2026')
+    conn = psycopg2.connect(host='127.0.0.1', dbname='arb_engine', user='arb', password='arb_engine_2026')
     cur = conn.cursor()
 
     cur.execute("""