Abstract: Real-time simulation of power electronics is currently an important tool in the research process of power electronic systems. In order to design an economical and reliable real-time simulation system of power electronics, this paper builds a hardware platform with the field-programmable gate array（FPGA） as the computing core and proposes a supporting electromagnetic simulation algorithm and the FPGA architecture design. Firstly, a simplified electromagnetic transient programs（EMTP） algorithm is derived to improve the parallelism of traditional off-line algorithms. Secondly, the virtual power loss problem of the fixed-admittance switch model is analyzed from the perspective of the numerical algorithm, and an initial error correction algorithm is proposed to eliminate the power loss. Thirdly, in tandem with the above algorithms, an FPGA architecture with digital signal processing（DSP） hardcore resource reuse based on the state machine framework is designed to realize the efficient utilization of resources in the way of hardware resource reuse, which improves the utilization efficiency of the FPGA without loss of speed. Finally, the effectiveness and correctness of the proposed method are verified by several real-time simulation cases.