Abstract: In view of the problem that photovoltaic system is ignored in the calculation and analysis of short-circuit current in power grid, this paper studies the characteristics of three-phase steady-state short-circuit current of photovoltaic system based on low voltage ride through control strategy of photovoltaic system. A calculation model of three-phase short-circuit current of photovoltaic system is proposed and verified with experimental tests. As a result, the short-circuit current model proposed in this paper is consistent with the real short - circuit characteristics, which verifies the correctness and effectiveness of the model. The research results and the model can be used to calculate and analyze the short - circuit current in photovoltaic convergence area.