As the core component of coal mine transportation system, the middle trough of scraper conveyor is subjected to the impact of gangue, coal block and chain friction for a long time, which leads to serious wear and tear. Traditional repair technologies such as surfacing welding and plasma cladding have problems such as large heat affected zone, high cost or complex process. In this paper, a new process for repairing the middle groove wear-resistant plate based on diamond coating technology is proposed. The diamond particles are compounded with metal alloy powder, and the high hardness wear-resistant coating is prepared on the surface of NM360 substrate by vacuum heating fusion process. The experimental results show that the average hardness of the coating layer is HV2100, which is 5 times higher than that of the substrate ( NM360 ), and the wear loss is only 0.08 g ( substrate 0.42 g ). This technology provides an efficient and low-cost solution for the repair of the middle trough under high gangue content and heavy load conditions by optimizing the coating gradient design and process parameters, taking into account the wear resistance and impact resistance.