The present disclosure provides a system for controlling a wound rotor synchronous motor including: a current/voltage determiner configured to determine optimum rotor current using a map from real-time motor operating information and to determine and output a rotor voltage according to the determined optimum rotor current, and a temperature estimator configured to calculate and output a rotor coil temperature from the rotor voltage and the optimum rotor current output from the current/voltage determiner using a rotor coil temperature estimation equation set from a correlation equation between the rotor voltage and the rotor coil temperature for each rotor current.