According to the problems in limited control set model prediction control system, for example, when weak power grid is connected to the grid, the power grid impedance can not be ignored, when power grid voltage is changed abruptly and when the system has time delay, current tracking precision is low, this paper proposes the reference current vector angle compensation method and switching weight coefficient constraint method. Firstly, the traditional three-phase grid-connected inverter finite control set model is built to predict the current control model. Secondly, the reference current vector angle compensation method is used to compensate the error of predicted current reference value so as to make up the error from the grid impedance and system current fluctuation, the switch function optimization weight coefficient is added to make the system have the characteristics of two-objective optimization, at the same time, when the power grid voltage abruptly changes, the system meets the requirement for grid connection, and the dynamic current tracking precision is high. Finally, Matlab/Simulink simulation verified the rationality and effectiveness of the method.