The internal stress of the glass material directly affects the processing quality of the glass parts and the service life of the optical components,and is highly valued in the fields of aerospace,precision optical systems,precision machining,etc.High sensitivity,large measurement range of stress detection technology has become a hot research topic.In this paper,a stress measurement method based on laser feedback effect is proposed.The laser feedback system consists of a laser and an external mirror,and the sample to be tested is placed in the feedback cavity.Due to the birefringence effect caused by stress,the stressed sample splits the external cavity into two "physical lengths",and the different external cavity lengths determine the phase of the feedback light in different polarization directions.The feedback light of different phases modulates the internal gain of the laser,so that the output light of the laser produces a phase difference in the orthogonal direction.By extracting the phase difference information,the magnitude of the stress can be obtained.The relationship between the phase of the output light of the laser in the feedback direction and the stress birefringence of the external cavity is analyzed theoretically.The phase information of the intensity tuning curve of the birefringent external cavity laser feedback system is obtained by Fourier transform.Finally,the internal stress of different aircraft cockpit glass samples was measured by laser feedback system,and the measurement results were given.The method has the advantages of simple structure and high precision,and has the potential to be applied to a glass material production line and to improve the preparation process.