Abstract: Based on the sealing mechanism of fault and its influence factors, we chose six main factors influencing the sealing of faults as the evaluation parameters. Through grading and using method of weighted average value, achieved weight values of comprehensive evaluation for fault sealing. This evaluation method was discussed and used in W1, W2, W3, W4 fault of Wangjiatun gas field and in S1, S2, S3, S4 fault of in Sanzhan gas field. The evaluation results are closer to actual geological conditions.