To reduce the accident, a radar speed measuring and monitoring system based on DSP chip-TMS320F2812 is designed in this paper. Continuous wave radar is used to receive echoes which are reflected from moving vehicles and frequency spectrum is analyzed with FFT. And then, velocity is calculated with the Doppler effect formula. Finally, the velocity is uploaded to the monitoring center by RS-232 UART. An experimental platform is produced and do the experiment by this method, simulation and experimental data show that it is an effective way to improve the speed-measuring accuracy and reduce accident rates.