In this paper, we present a Field Programmable Gate Array (FPGA) based high-performance gait control system for passive bipedal robots with complex mechanical structures and multiple degrees of freedoms in body and limbs. The system utilizes the hardware and software reconfigurable feature of the advanced FPGA device to achieve intelligent bipedal gait control. We implement central processing unit, sensor data processing module, gait control module, pulse width modulation module and data transmission module inside the FPGA chip. All the modules can be duplicated and reconfigured to control as many motors as needed. In addition, we design a gait control strategy with the method of phase transfer map. To estimate the control system, we create bipedal robots with passive dynamic gaits. Satisfactory experimental results demonstrate that the FPGA-based gait control system is a flexible, high-performance solution for the locomotion control of passive bipedal robots