A system for implementing cache sharing includes a main control unit and a plurality of service processing units, and further includes a shared cache unit respectively connected with the main control unit and the service processing units for implementing high-speed data interaction among the service processing units. A method for cache sharing is also provided. In embodiments of the present invention, based on a reliable high-speed bus, a high-speed shared cache is provided. A mutual exclusion scheme is provided in the shared cache to ensure data consistency, which not only implements high-speed data sharing but also dramatically improves system performance.