Abstract: To increase the accuracy of knock detect and control of gasoline engine, discrete wavelet transform(DWT) and Field Programmable Gate Array(FPGA) were applied to knock control. Knock edge feature was extracted from vibration signal by using DWT. A parameter of relative energy for knock intensity evaluation, and a knock feedback ignition control strategy were proposed. The knock control model was established, verified by simulink test, and actualized on FPGA. The results show that the knock control method based on DWT and FPGA can diagnose knock accurately, is suitable for realtime control, and can make gasoline engine work at slight knock area, which is useful for improving the performance of gasoline engines.