Abstract: A new method for the evaluation of stress in cold rolled strip based on magnetoelastic effect is presented. The sensor output characteristics were studied and its magnetic stress detection principle was also described. Using the ANSYS finite element method,simulation analysis of the structure carrying capacity of the calibration device model was conducted. Choosing a 50 Hz sinusoidal AC excitation system,a magnetic elastic stress measurement system prototype with the gap of 1.5 mm was developed. A performance testing platform was built to characterize the sensor output test of the prototype. The testing results show that the device can achieve linear response for stress in the steel sheet and provide a new way for the wide application of the magnetic elastic stress measurement technology.