Ring varistors test equipment needle is often located in the insulation porcelain body between the two electrodes in the test on its electrical performance testing and sorting, the voltage measurement value exceeds the limit, causing false positives to the test results.So many good products are sorted to unqualified warehouse and retest positions, qualification rate of one test is low. Therefore, retesting treatment must be done. To solve this problem, the vibration test machine feeding part and testing subsystem were analyzed, reasonable scheme was put forward, the pre inspection and error proofing part were focused on. Through verification and implementation, the test accuracy of testing machine is greatly improved.