The invention discloses a security mechanism method for video monitoring and recording playback of digital signage. The method comprises the steps of obtaining an RTSP (Real-Time Stream Protocol) playing and recording address; starting a video recording function; setting a video monitoring address list; setting the position and size of a video monitoring window, and a monitoring duration interval; starting circular video monitoring; and displaying images. Through adoption of the method, the window position and window size can be set randomly; the circular video playing list and video monitoring interval switching time can be set; and the video monitoring and recording playback problem of the digital signage is solved.