A method of correcting a target angle error of a radar sensor, the method may include recognizing a first target angle of a target through the radar sensor; recognizing a second target angle of the target through V2X communication and then calculating a target angle error between the first target angle and the second target angle; comparing the target angle error with a predetermined critical error; and correcting a phase curve of the radar sensor by applying the target angle error to the phase curve in accordance with the comparison result, and then giving a target warning using the corrected phase curve.