With the rapid development of science and technology in China, induction motor is not only the most widely used motor in traditional industrial and agricultural production, but also a widely used power source in the field of electric vehicles and aerospace science and technology. Therefore, the overload protection technology in motor also needs to be more and more intelligent. A more intelligent protection method is proposed based on the traditional resistance overload protection, which realizes the real-time identification of stator resistance during motor operation, and then the internal temperature of the motor can be calculated directly through the relationship between resistance and temperature. Moreover, a 1DPT160M series variable frequency speed regulating induction motor is used for experiments to verify the feasibility of the method, which provides a new principle for overload protection technology of motor protector.