The invention relates to an automatic transfer switch driving electric motor power supply by intelligent adjustment, comprising a voltage identify unit, a signal processing unit, a relay control unit,a CPU, and a driving electric motor transferring a switch automatically. The voltage identify unit inputs the signal into the input end of the signal processing unit, and one I/O1 mouth of the CPU isconnected with the output end of the signal processing unit; the relay control unit comprises 4 to 6 relays; The input ends of six-phase voltage of the common-used and spare power supply are respectively connected with the six input ends of the multi-gating circuit composed by the relays; the relay multi-gating circuit has the output end connected with the driving electric motor; the other 4 to 6interfaces are respectively connected with the ends of 4 to 6 relay control coils by the CPU; the other ends of the control coils are connected with low-levels. For the distribution network of two circuits power supply, the present switch improves the reliability of the system power supply and avoids that the power supply can not be transferred reliably when a single power supply is the driving power of the mechanism and breaks down; the invention makes the system safer and more applicable by setting the undervoltage and overvoltage value according to the need of load.