An information management system for high voltage electric equipment test data based on B/S three-layer network structure is developed. There are plenty of test data produced annually by the preventive tests for the high voltage electric equipment in power bureaus， which makes the manual type management difficult. This system helps to manage the data on the insulation state of high voltage electric equipment by using the computer database instead of manual work. The test data is saved in the computer database to be read by software in real time for examination and analysis. Through the appraisal of the expert system for the insulation state of high voltage electric equipment， the system can give the results of qualification judgment， curve fitting， trend analysis， and chromatography analysis of transformer oil. Using the internal network resources in the power bureau， it can deliver the information on the insulation state in the local area network. It can also upload the latest test data information level by level， and report it to leaders in a unified manner. The system is propitious to people concerned in collecting and analyzing the information on high voltage electric equipment test data， according to which accurate decisions on the management of equipment can be made.