The invention belongs to the technical field of intelligent transportation and particularly relates to a traffic OD information collection system based on a WiFi probe and a processing method. The system comprises an acquisition module, a processing module, a storage module, an analysis module and a service display module, wherein the acquisition module collects and records original user data in real time through the WiFi probe arranged in a monitoring area. The processing module preprocesses the original user data recorded by the acquisition module and generates user data. The storage modulestores the user data. The analysis module performs association analysis and data retrieval on the user data and generates an OD matrix. The service display module updates and displays a road traffic condition in real time according to the OD matrix. According to the invention, the long-term and dynamic traffic OD information of pedestrians and vehicles in urban roads is achieved, a classified traffic OD matrix is obtained, and data is provided for realizing dynamic allocation of OD flows and traffic planning.