In the case of the sharply declining of well production caused by water blockage, which was caused by maintenance operation due to the difference between layers in Shuanghe oilfield. A new type of waterlock-proof treatment agent is developed through laboratory experiments (0.5%SATRO+0.05%alkyl sodium sulfonate+0.03%FX-02). This paper mainly introduces the formulation screening of the waterlock-proof treatment agent and the performance evaluation.The results show that:this product can effectively reduce the interfacial tension between oil and water, causing the interfacial tension to reach ultra low（10-3 mN/m）; at the same time, the product with a good demulsification performance can make the demulsification rate up to 90% in 3 h; the laboratory core physical model experiment indicates that : when the injection rate of the waterlock-proof treatment agent is 10 PV, temperature of 70 ℃, displacement pressure of 0.3 MPa, reaction time up to 8 h, the remaining ratio of the core permeability reaches up to over 85%, which can effectively prevent emulsification blocking and the formation permeability damage caused by water lock effect. The waterlock-proof treatment agent has been applied in field for 12 wells, whose effective rate is 100%, remarkable results are achieved.