The invention belongs to the technical field of a testing method for an electric system stabilizer and particularly relates to a testing method used for an electric system stabilizer and based on CoCo-80. The method comprises the following steps of uncompensated phase frequency characteristic testing of an excitation control system, parameter setting of the electric system stabilizer, gaining andcritical gain determination, motor loading step change testing and antiregulation testing. According to the method, the aims of software configuration of CoCo-80 in a test, a wiring method and testingthrough CoCo-80 are achieved. The method has the advantages that the system is convenient to carry, the working time of a battery is long, and the testing demand can be completely met. The method canbe applied to electric system stabilizer testing of all power generation factories, dynamic and static signals of a power generator excitation system are more precisely measured and recorded, the phase frequency characteristic of a power generator excitation regulator is more effectively measured, the parameter of the electric system stabilizer is precisely set, and the effect of the electric system stabilizer on inhabitation of low-frequency oscillation is more efficiently verified.