The sedimentation chamber is a key dust removal component in waste heat boilers, during boiler operation, the heat-exchange fumes entering the subsidence chamber will be mixed with a large number of dust particles, high-speed dust particles hit the flue wall, resulting in the wear of the flue wall. This paper is based on the EDEM-Fluent coupling method to study the flue wear characteristics in the settling chamber of the waste heat boiler. The dust concentration in the flue gas stream is 55g/Nm3, the particle size of the flue gas is 1mm, the particle density is 2500kg/m3. Comparative analysis of the flow field characteristics of each section and the particle distribution in the flue under three different intake loads of 0.8Vt, 1.0Vt and 1.2Vt. At the same time, the Archard wear model is introduced to obtain the wear distribution and wear law of each part of the flue ,The result shows that The relative wear of the second ash hopper increased from 28% to 37%, the relative wear of the upper part of the ash baffle increased from 20% to 27%, and the relative wear of the first ash hopper decreased from 17% to 9%. The reason for the change in the amount of wear can be attributed to the change in the flue gas flow rate and particle distribution. After the flue gas flow enters the sedimentation chamber from the entrance, the velocity first increases and then decreases. The flow velocity reaches the maximum at the second ash hopper and the ash baffle, and a longitudinal swirling flow is formed at the second ash hopper, and some particles follow the flue gas flow. The rapid ascent collides with the wall, which makes the wear degree of the No. 2 ash hopper obviously greater than the rest of the parts under all working conditions. At the same time, the increase in the load also makes the distribution of particles show a tendency to accumulate in the No. 3 ash hopper, and the number of particles settled from the No. 1 ash hopper is reduced, and the amount of wear is reduced. The collision of a large amount of accumulated particles with the wall of the No. 3 ash hopper increases the wear of the No. 3 ash hopper.