In order to improve the reliability of the microwave vehicle detection technology, we develop linear frequency modulated continuous wave (FMCW) radar to provide accurate and reliable traffic data.The vehicle detection radar consists of front-end unit and data processing unit.IVM-297 microwave module is selected as the microwave transceiver sensor, and triangular wave circuit is designed to generate the modulation signal.Then, we choose FPGA module as the data processer to take advantages of its parallel processing capabilities, as well as the integrated "FFT CORE".Windowed FFT is used to analysis the spectrum character of the output intermediate frequency (IF) signals.At last, background subtraction method and maximum spectral peak detection method are used for vehicle detection applications.The developed FMCW radar is able to achieve the basic goals of vehicle detection, and lays a foundation for further research.