Abstract: An electronic auxiliary device is adapted for being joined with a wrist strength training device and wirelessly coupled to an information device, as well as the electronic auxiliary device comprises a device body and a function device. The device body has an auxiliary unit and is adapted for being joined with the wrist strength training device. The function device is disposed inside the device body. The function device is capable of acquiring the exercise information and transmitting the exercise information to the information device wirelessly, so as to compute the exercise information by the information device or to interact with the information device through the exercise information. Therefore, the wrist strength training device has both training and entertaining effects.