The invention provides a method for allocating tasks. The method is implemented in a server for allocating the tasks. The server is connected with a plurality of electronic devices. The method includes steps of allocating certain electronic devices as optional devices for target application programs; receiving target tasks with target task information; selecting target devices from the optional devices for the target application programs indicated by the target task information and executing the target tasks. The certain electronic devices conform to the quantities of the optional devices for the target application programs. The target tasks are released by users. The invention further provides the server for allocating the tasks. The method and the server for allocating the tasks have the advantages that owing to the method and the task server, the application programs do not need to be frequently switched over when the tasks are executed by the electronic devices for executing the allocated tasks, the task execution efficiency can be improved, and the storage costs of the electronic devices can be reduced.