A system of recognizing identity of object and method of automatically recognizing identity of object are provided. The method is to shoot a monitoring region for obtaining a monitoring image, recognize an object image in the monitoring image, scan the monitoring region for retrieving each identity data of each wireless badge, determines each image position of each object image in the monitor region, determine each badge position of each wireless badge in the monitor region, and link the object image and the identity data together when the positions match with each other. The system can pair the object image with the identity data instantly, determine whether the object is unregistered, and effectively save the time and human resources required by artificially pairing the object images with the identity data.