The invention relates to a voltage sag endurance capability test method and system. The method comprises the steps that: the longest endurance time of to-be-tested equipment in a test environment of which the voltage amplitude is 0 is found through the dichotomy; based on the longest endurance time, whether the to-be-tested equipment is type I tolerance equipment or type II tolerance equipment isdetermined by increasing the voltage amplitude; and based on the type of the tested equipment, the to-be-tested equipment is tested through a preset method, so that a tolerance curve is obtained. According to the voltage sag endurance capability test method and system of the invention, the to-be-tested equipment is classified as the type I equipment or the type II equipment according to the longest tolerance time; the corresponding test method is adopted according to the tolerance curve characteristics of the different equipment types; and therefore, test speed is increased. The type I equipment and the type II equipment are tested with respective corresponding test methods corresponding to the type I equipment and the type II equipment, and the tolerance curve shape characteristics of theto-be-tested equipment are considered, and therefore, test precision is improved.