The invention discloses an RCS detection system based on binocular vision, and a detection method thereof. The system and the method can realize that during RCS detection, a detected object and a detection scene are subjected to three-dimensional reconstruction, a three-dimensional scene coordinate system is converted to be consistent with a world coordinate system, namely an RCS detection coordinate system, and an RCS detection numerical value is superposed with a reconstructed three-dimensional model, so the RCS characteristic value of the position of the measured object can be accurately checked. For example, a stealth aircraft is parked on a parking apron or a hangar, 360 DEG shooting is carried out around A stealth aircraft through a binocular vision camera, three-dimensional reconstruction of the stealth aircraft and the parking apron or the hangar is achieved, a three-dimensional model of a measured object is generated, meanwhile relevant coordinates of the stealth aircraft and the position of the stealth aircraft are generated, then the RCS detection value of the stealth aircraft in a world coordinate system is acquired, the RCS detection value and the three-dimensional model of the stealth aircraft are superposed through a computer, the condition of the stealth aircraft is analyzed, and related information is fed back.