The invention provides a method for shortening the time of testing the cycle life of lithium ion batteries. According to the method, N batteries are selected for testing of the cycle life, and the cycle life of each battery is tested in different SOC (charged) states. In this way, the testing time for the cycle life of lithium ion batteries is greatly shortened, the testing cost is reduced, the introduction time for new products and new technologies is accelerated, and the product competitiveness for battery manufacturers and relevant material manufacturers is improved. According to the method, if 4<=N<=10, the testing time can be greatly reduced, the testing accuracy is high, and not too many testing devices will be occupied; if N=4, the testing time is 50%-70% reduced; if N=6, the testing time is 65%-75% reduced; and if N=10, the testing time is 70%-80% reduced. A difference between a capacity result obtained by the method and a capacity result of a conventional method is within 5%, and a difference between a thickness result of the method and a thickness result of the conventional method is within 8%. Therefore, it is proved that the method of the invention is greatly consistent with the conventional method.