The invention discloses a software-defined edge computing system oriented to Internet of Things and a resource allocation method, and the system comprises multi-access base station equipment deployedin a cellular manner, an edge node EN with data processing and computing functions is deployed at each base station, and meanwhile, the EN is connected to a centralized computing resource pool througha high-speed optical fiber. A software defined network and network function virtualization concept is introduced, a data level and a control level are separated, and a network function is decoupled from hardware equipment. An OpenFlow controller is adopted to realize centralized control, mobile management, data processing and resource distribution functions are executed upwards through a programmable application program interface, and the OpenFlow controller is communicated with a transponder downwards through an OpenFlow interface to realize forwarding of user data. Different characteristicsof the Internet of Things terminal user are considered, and the Stackelberg game is applied to the distribution process of computing resources of the Internet of Things terminal user, so that the resource utilization rate is improved to the maximum extent on the premise of ensuring the service quality of the user, and the requirements of more different types of users are met.