Multi-quadrant laser fuze system and working principle are analyzed. Field Programmable Gate Array(FPGA) features some characters, including small size, high integration of circuits and rich chip interfaces, which are helpful to realize the miniaturized design of signal processing circuits and complex algorithm design of fuze. According to software algorithm simulation and overall test, the signal processing circuits based on FPGA satisfy the real-time requirement of fuze. The signal processing procedure is given as well. The anti-interference algorithms toward the sunshine interference and cloud interference and target recognition algorithm can enhance the anti-interference ability of fuze.