The invention relates to an automatic station adjusting device and method for a shaft straightening machine, and belongs to the technical field of precision machines. A working platform and a working pedestal are connected through a rail in a sliding manner, and the working platform is provided with a left centre, a right centre and a plurality of supports which are connected with the working platform through respective locking mechanisms; and a station adjusting mechanism is fixedly connected with the working pedestal. Current positions of the left centre, the right centre and the multiple supports are obtained by positioning sensors, then a movement path is calculated according to target positions, and finally a connecting rod of the station adjusting mechanism conducts repeated unlocking, movement and locking operation on each locking mechanism so as to form new station distribution. The automatic station adjusting device and method have the beneficial effects of being convenient to operate and accurate in positioning, and automatic station adjusting can be carried out according to different application occasions.