The invention discloses a simulation circuit and system for an electric system. The simulation circuit comprises a signal input circuit, a plurality of voltage power amplification circuits, a plurality of parallel current-sharing control circuits and a parallel output circuit, wherein the signal input circuit is connected with a digital simulation system, and used for receiving simulation analog signals; the voltage power amplification circuits are connected with the signal input circuit, and used for conducting power amplification on the simulation analog signals, so as to obtain power amplified signals; each parallel current-sharing control circuit is connected with the corresponding voltage power amplification circuit; the parallel current-sharing control circuits are used for conducting current-sharing on the power amplified signals, so as to obtain a plurality of parallel current shared signals; the parallel output circuit is connected with the parallel current-sharing control circuits, and used for combining the parallel current shared signals into a simulation signal. Through the adoption of the simulation circuit and system, the problem of inaccurate power network simulation results caused by low output signal amplitude value and low output power of a power amplifier in the prior art is solved; power capacity expansion and voltage grade improvement of a power amplifier are simulated, so as to ensure accurate simulation results.