Abstract: We set up a simulation model of the unmanned surface vehicle in defending target. We first made digital and non\|dimensional processing of the target threat index, and then calculated the weighted correlation degree of each suspicious object. We used the grey correlation algorithm to sort multiple suspicious targets, and then determined the degree of threat about each suspicious target. Unmanned surface vehicle based on the degree of threat to intercept priority to solve the uncertainty of the threat degree of multiple suspicious targets in the simulation environment of the security target. The simulation results show that this method is more accurate than the traditional threat assessment method, and improves the reliability of the unmanned
surface vehicle defending the goal.

Key words: unmanned surface vehicle, weighted correlation degree, grey correlation method, threat of sorting