The invention provides a test method for electric endurance of a switching capacitor set beaker of the extra-high voltage project. The method passes the Acceptance Test Procedure (ATP) simulation verification, test results meet the standard and all requirements of the extra-high voltage project for the switching capacitor set test, a synthetic loop and an inductance-capacitance (LC) oscillating loop are used for testing, the loading investment of a test station for test devices is reduced, and the device safety hazards caused by long-time and large-quantity electrical endurance tests can be reduced.