The invention relates to a content delivery network (CDN) quality monitoring method. A CDN comprises a data center, a bandwidth provider switch and edge nodes. The method includes the following steps that monitors in the data center carry out packet internet grope (PING) testing on node servers; the monitors in the data center carry out PING testing on the bandwidth provider switch networked with the data center; the monitors in the data center carry out testing on the edge nodes, if the edge nodes are controllable nodes, at least a part of PING testing, downloading rate testing and page Poll testing are carried out, and if the edge nodes are uncontrollable nodes, PING testing is carried out; the controllable nodes are edge nodes, capable of being logged into by a supervisor of the data center through the network and deploying downloading rate testing and page Poll testing, of HTTP website service, and the uncontrollable nodes are edge nodes, incapable of being logged into by the supervisor of the data center through the network or deploying downloading rate testing or page Poll testing, of the HTTP website service.