diff --git a/webapp/controller/ComputingPowerController.class.php b/webapp/controller/ComputingPowerController.class.php
index bb55f48c..4b2aa1e0 100644
--- a/webapp/controller/ComputingPowerController.class.php
+++ b/webapp/controller/ComputingPowerController.class.php
@@ -71,7 +71,7 @@ class ComputingPowerController extends BaseAuthedController
             $totalNum = ComputingPower::getTotalBH($currentMeta['id']);
             $curr_period['period_begin'] = strtotime($currentMeta['start_time']);
             $curr_period['period_end'] = strtotime($currentMeta['end_time']);
-            $curr_period['assignable_cec'] = $currentMeta['cec_pool'];
+            $curr_period['assignable_cec'] = min($currentMeta['cec_pool'],$totalNum);
             $curr_period['total_exchange_hash_rate'] = $ownerNum;
             $curr_period['total_hash_rate'] = $totalNum;
             $curr_period['await_time'] = strtotime($currentMeta['end_time']) - myself()->_getNowTime();