Synchronous generator leading phase operation has become a widely used means of power grid voltage regulation. Dynamic simulation test is a kind of important research method of power system discipline. Due to the importance of the safety of power grid, it is not allow that actual deep leading phase test of generator be carried out. A method based on the dynamic simulation test for study on characteristics of large generator deep leading phase is proposed in this paper. And taking a 600 MW generator unit as the prototype, design the large synchronous generator leading phase operation dynamic simulation parameters such as generator, main transformer and circuit based on the similarity principle, and set the generator leading phase operation dynamic simulation system. dynamic simulation test on various working condition of different leading phase depth for generator model is carried out, and dynamic simulation test result is analyzed, influence factors of the dynamic simulation test precision is pointed out such as the simulation error of electrical parameters, the series impedance without saturation phenomenon and magnetic circuit saturation reflect not true under the simulation system capacity. A comparison of dynamic simulation test results of generator model established with leading phase test results of 600MW generator shows that the dynamic model design is correctness and validity.