A theoretical mechanics answer device comprises a support, a rotating disc, a plurality of detachable question modules, a sensor linkage module and a control module. The rotating disc is coupled to the support, the question modules are installed on the rotating disc, the sensor linkage module is used for driving the question modules to make corresponding actions, and the control module is used for controlling the sensor linkage module. The rotating disc is coupled to the support. The sensor linkage module is installed on the support through a first fixing part. The power output end of the sensor linkage module is connected with the corresponding question module, and the signal output end of an optoelectronic switch of the sensor linkage module is connected with the control module used for processing collected data. The theoretical mechanics answer device has the advantages that the abstract and recondite theoretical mechanics is reified and is visually achieved in a mechanical mode; the whole linkage mechanism is simple and efficient; the mechanism is simplified and is high in efficiency due to the innovative linkage design, the operation procedures are simplified, and synchronization of all the components is achieved; meanwhile, only one power source is used for the linkage device, so that the design of a control circuit is simplified.