Abstract: The paper analyzed the defect patterns of the lunar lander impacted by landing,and advised that developing on-line nondestructive testing to diagnose the lander before and after landing by using pulsed eddy current method,the method was conformed feasibly through experiments.For the damages mis-recognition caused by temperature drifting in the space wide temperature scope,it is suggested that the data could be compensated by the cooperation of the probe and the temperature transducer,and the compensated data vary linearly,the intersect varied regularly.The state changes could be recognized by the variation of the intersection curve Vs temperature,thus the method exhibited potential engineer values.