A calibrator for a camera includes a controlling circuit, a photographing circuit, a calculating circuit, and an instructing circuit. The controlling circuit is configured to control a movable body to move into a shooting area of the camera. A marker is provided on the movable body for calibration of the camera. The photographing circuit is configured to control the camera to photograph the marker. The calculating circuit is configured to calculate at least one parameter of the camera based on the photographed marker. The instructing circuit is configured to transmit the at least one parameter to the camera to calibrate the camera.