The invention relates to a chrominance subcarrier frequency test method and system for a video signal. The method and the system are used for obtaining line frequency of the video signal through the output of a synchronous video signal of a sine wave signal generated by a signal generator, and obtaining a chrominance subcarrier frequency value of the video signal according to the line frequency, so that a technicist can effectively judge the chrominance output quality of the video signal according to the chrominance subcarrier frequency value, so as to guarantee the display quality of the video and improve the user experience.