Portable front-end video detector and detection method thereof

The invention discloses a portable front-end video detector and a detection method thereof. The detector comprises an analog signal input end, a video collection card, a detection processor, a display screen, an analog signal output end, and a digital signal input end, wherein the analog signal input end is used for receiving an analog video signal output by a detected device; the video collection card is connected with the analog signal input end and used for collecting and converting the analog video signal to output a digital video signal; the detection processor is connected with the video collection card and used for detecting and processing the digital video signal; the display screen is connected with the detection process and used for displaying the detected and processed digital video signal; the analog signal output end is connected with the detection processor and used for outputting an analog video signal to the detected device; and the digital signal input end is connected with the detection proc