The present invention discloses a method, an apparatus, and a system for scheduling a processor core in a multiprocessor core system, which relate to the field of multiprocessor core systems, and can meet the demand for real-time network I/O processing, thereby improving the efficiency of the multiprocessor core system. The method for scheduling a processor core in a multiprocessor core system includes: obtaining, in the running process of the multiprocessor core system, a first control parameter, a second control parameter, a third control parameter, and a fourth control parameter; transferring a packet of a data flow that enters the multiprocessor core system to an idle processor core for processing based on the first control parameter, the second control parameter, and the third control parameter; and switching over the processor core in the multiprocessor core system between an interruption mode and a polling mode based on the fourth control parameter.