In order to improve the reliability of the scraper conveyor scraper, the SG650 scraper conveyor was taken as an example to establish the engagement model, and the stress changes of the chain in the engagement process was analyzed. The analysis results showed that the maximum equivalent force of the scraper conveyor chain was 436 MPa, which was less than the yield limit of the material, and the overall structure of the chain was safe. The maximum stress point of the flat ring was located in the contact area of the vertical ring. The optimization of the 2 chains was suggested from improving the reliability of the chain.