Due to the large quantity of image data, the complexity of algorithm for moving objects detection and the real-time requirement in practical applications, a real-time moving objects detection system is designed which is constructed with the DSP chipset TMSC320DM642 as the core. An algorithm for moving objects detection based on Gaussian Mixture Model and Three-Frame Differencing is proposed to detect the moving objects. The experimental results indicate that the system can effectively detect moving objects and meet the real-time requirements.