The invention provides a complex task allocation method based on a server-free fog computing system architecture, which comprises the following steps that 1, terminal equipment sends a task request toa fog node, and the fog node receives the task request and transmits the task request to an application layer to start service; 2, an access control module of the application layer performs access control on the task request; 3, the access control module transmits the task requests allowed to be accessed to a request forwarding module of the application layer to perform priority ranking of the task requests; and 4, the request forwarding module transmits the sorted task requests to a service manager of the application layer, and the service manager performs difficulty judgment and allocationon the task requests. According to the complex task allocation method based on the server-free fog computing system architecture provided by the invention, task request allocation can be carried out according to the performance of the fog node, a cask effect is avoided, the service delay of a large task is reduced, and the task request of a high-mobility and high-dynamic scene is effectively solved.