The invention relates to a simulation method of an electric power system based on the compression and the division of frequency-related network equivalence, and belongs to the technical field of the dispatching automation of electric power systems and the simulation of electric grids. The simulation method comprises the following steps: firstly, removing the redundancy of frequency-related network equivalence in a mathematical model through compression processing so as to decrease the whole calculated amount; making frequency-related networks equivalent by sub-block processing, and establishing a plurality of subblocks so as to realize parallel computation. The simulation method can effectively solve the problem that when the frequency-related network equivalence is applied to the electromagnetic transient simulation of the electric power system, the calculated amount of single frequency-related network equivalence module is too large. Through the adoption of the simulation method disclosed by the invention, the simulation velocity of the electric power system can be obviously accelerated, and the practice effect of engineering is satisfied.