The invention relates to a life tester for an alternating-current contactor and a control method thereof. The life tester consists of a test control cabinet, a specimen cabinet, a 1/6Ue power supply cabinet and a load cabinet, wherein the test control cabinet comprises an industrial personal computer, a driving circuit and a contact state detection circuit; the specimen cabinet comprises a first accompanied specimen, a contactor specimen and a first breaker; the 1/6Ue power supply cabinet comprises a second accompanied specimen and a second breaker; and the load cabinet comprises a load circuit. The life tester is controlled by the industrial personal computer, so a life test of the alternating-current contactor can be completed automatically and accurately, and the automation level of the life test is improved; and four electrical life tests of a switch-on test, a break-off test, a dead load test and a variable load test of the alternating-current contactor can be performed, and a mechanical life test of the alternating-current contactor also can be performed. The life tester has an integral data protection function, namely test data is not lost in case of unexpected outage, the collected test data is not damaged after the power supply restores, and the test data is saved perpetually.