Abstract: During the coal cutting process of the cutters on the coal shearer, due to the high compressed stress, shearing force and dynamic load, the cutter could not realize a high efficient coal cutting and others of the coal shearer. A stress detection method of the cutter on the coal shearer was provided based on the strain sensor. The detection method was to conduct the real time detection on the cutter stress during the coal cutting process of the coal shearer with a method to stick the strain gauges on the cutters and a stress variation curve of the cutter could be real timely displayed. The test results showed that during the coal cutting period of the coal shearer, the stressed variation curve of the cutter could actually reflect the cutter stressed and the max X directional force of the cutter 1-1 selected would be about 0.70 kN. The max Y directional force value would be 1.72 kN. The max Z directional force value would be 4.16 kN and the torque of the cutter 1 would be 0.59 kN·m. In consideration of the influences of the error and related random factors, the test results closed to the related theoretical calculation value could realize the stress detection of the cutter. The study could realize the pre-judgement on the wear degree and the failure status of the cutter on the coal shearer, could timely found and replace the failure cutter and would have the important significances to improve the work efficiency and service life of the cutting head on the coal shearer.