The invention relates to a heterogeneous function equivalent dispatching device and method. The heterogeneous function equivalent dispatching device comprises a plurality of heterogeneous function equivalent for providing the same function for external service requests, and further comprises a redundancy controller and an input agent device. The redundancy controller receives a triggering signal given by the input agent device and randomly selects the heterogeneous function equivalent for providing services for the external service request according to received externally-input control parameters. In this way, by means of the method of randomly combining and dispatching the heterogeneous function equivalents, the device has different complex rates on the structural representation layer, the heterogeneous function equivalents selected according to the service requests are different, the heterogeneous function equivalent results output according to different dispatch strategies are also different, dynamically-variable output states are shown to the outside, and then loaded back doors or vulnerability cannot be detected or used by an attacker. The device has auto-immunization capacity for a plurality of unknown security threats possibly existing in a network system.