Objective,2,To explore the application of three testing methods, namely visual inspection method, insulation tester and insulation tester combined with magnification with light source, in the testing of insulation performance of electrosurgical instruments.,Methods,2,Two hundred and ninety electrosurgical instruments were selected from October 2020 to March 2021, and their insulation properties were examined by visual inspection, insulation detector and insulation detector combined with light source magnifier.,Results,2,The three methods of visual inspection, the insulation detector and the insulation detector combined with a light source magnifying glass detected 3.45%, 11.03% and 15.52% of insulation breakage, respectively,p,<,0.05, with statistically significant differences. The differences were statistically significant.,Conclusion,2,The visual inspection method is time consuming, laborious, has a low detection rate and is prone to leakage, and is not recommended for routine use. The Insulation Tester is an efficient, accurate, time- and labour-saving method for detecting insulation faults and can be used for daily testing of the insulation properties of electrosurgical instruments. The Insulation Tester combined with a lighted magnifying glass provides a more comprehensive and accurate detection of existing and potential faults in the insulation and can be used for regular testing of the insulation of electrosurgical instruments as it is relatively time consuming and labour intensive. Both of the latter are effective in preventing the risk of leakage from electrosurgical instruments and are of great importance for surgical safety.