The traditional stroboscopic photography experiments are usually carried out in a dark room with strict environment requirements．It designs and develops a mono-pendulum stroboscopic photography system based on USB camera，which can be used in bright classrooms conveniently and efficiently．The motion of mono- pendulum is captured by USB camera in real time，then the relative position of the ball is acquired by inter-frame difference method and the stroboscopic photograph is generated by one click to display the motion track of the ball，and the period of the ball is calculated by Fourier transform．Experimental results show that the system can meet the requirements of experimental teaching well with high accuracy and intuitive demonstration．