The digital simulation method on basis of e^AT presented in this paper consists in treating oarious continuous，1inear，constant parts of the system simulated as subsystems which are desoribed by systems of discrete state equations. Then，these subsystems and various non-linear or time-varying parts are interconnected and thus digital simulation of the whole system is implemented. This method of simulation possesses the merits of fast computing rate，high accuracy and versatilety. The main point described in this paper is concerning the computation of the coefficient matrixes of the subsystems using analytir method which has the merit in the amount of computation and accuracy of simulation independent of the step size chosen with the (somewhat laboursome) program.