CDN video buffer system and method

The invention relates to a CDN (Content Delivery Network) video buffer system, comprising a CDN management server, a content management platform, a plurality of buffer servers, a source server, a plurality of clients and a database server. The invention also relates to a CDN video buffer method which obtains the times of film sources being visited by clients in a certain period in real time from the plurality of buffer servers, and only when the times of being visited reach a threshold value can the film sources being buffered in the buffer servers. In addition, the system comprises performing priority annotation on each film source in the system, buffering film sources with high priorities into the buffer servers, and deleting film sources with low priorities when the capacities of the buffer servers are full. The CDN video buffer system and method optimize buffer capacity management, avoid frequent buffer replacement and bandwidth waste, and are widely applied to the fields of video click or live video, and network video monitoring.