In order to improve the current collection ability of high-speed train and reduce the off-grid rate, this study designs the active controller of pantograph based on linear quadratic optimal control. Aiming at the problem of weight matrix Q and R in the linear quadratic optimal control, genetic algorithm is used to optimize. The objective function of the system is calculated by the dynamic performance index of the system and the optimal value of the weight matrix is obtained. And it solves the problem that the weight matrix is difficult to realize the global optimal in traditional linear quadratic optimal control by the experience design. Through the simulation and analysis of the change of catenary stiffness and the change of contact pressure parameters between pantograph and catenary at different speeds, the active controller designed in this study can reduce and control the fluctuation of contact pressure, and improve the dynamic performance index of pantograph and catenary system.