To explore the issue of easy breakage of the scraper conveyor dumbbell pin, through a combination of experimental research and fatigue analysis of dumbbell analysis. First,the force model of dumbbell pin was established,in which the pin used ANSYS dumbbell finite element was analyzed then the stress distribution results were obtained. By using the load testing system for the dumbbell pin,the loading data of dumbbell pin in the actual work were obtained; the n-Code Design Life was used to extract the maximum loading data of the dangerous area. And the rain flow counting and fatigue life analysis were carried out. The results show that: Dumbbell pin damage is from the dumbbell pin neck stress concentration of the largest region of the formation of fatigue,when the crack propagation area to a certain extent after the arrival of fatigue fracture zone,so that the entire dumbbell pin fracture. According to the working conditions of the scraper conveyor,the time of crack of the dumbbell pin is 92 days. The paper provides a design basis for the structure improvement of dumbbell pin.