In order to further increase the measurement range of optical fiber stress sensor, an optical fiber Mach-Zehnder interference(MZI) stress sensor based on the interference of vortex beam and plane wave beam is designed, and a new stress demodulation model is proposed. The principal component analysis method is used to extract the main features of the fork interference pattern set, and the relationship between the phase difference between the two beams and the correlation coefficient of the corresponding interference pattern for the main features is obtained. According to the stress phase difference relationship, the relationship between the stress and the correlation coefficient is obtained, a stress sensing experimental system based on the interference between vortex beam and plane wave beam is built, and the stress sensing response characteristics of the system are studied. The experimental results show that the stress response sensitivity of the sensor is 0.25694 rad/MPa, and the maximum stress measurement range is 3392 με。