Abstract: Manual surveillance method of digital video monitoring system may lead to fatigue failure. The paper proposed a detecting method of moving human in coal preparation plant. The method uses background subtraction method to separate moving targets, uses Gaussian mixture model for background modeling, and continuously updates the background model to improve accuracy of motion detection. On the basis of accurate detection of moving targets, the method would detect and mark the human target combined with body shape information. Experimental results showed the method can accurately segment some targets of moving human, and meet with real-time requirements. But the method cannot segment some obscure or connected targets of moving human which needs further studying.