Serious erosion problem of the heat exchanger directly affects the safe and steady operation of waste heat utilization systems. Herein, a honeycomb H-type finned tube heat exchanger for waste heat utilization of dusty flue gas was proposed, and the collision and erosion behaviors of fly ash particles were numerically predicted via the discrete particle method (DPM). Firstly, the single factor analysis was used to investigate the effects of each structural parameter on the erosion rate. Then, the range analysis of different levels of different structural parameters was carried out via orthogonal test method. Finally, the prediction correlations of erosion rates were obtained based on multiple regression method. The results shows that the oblique tube pitch and fin pitch are negatively correlated with the erosion rate, while the slit width, fin height and fin thickness are positively correlated with the erosion rate. Among them, the fin pitch has the most significant impact on the erosion rate, while the effect of oblique tube pitch is the least. The optimized case (A4B2C3D1E4) was obtained by orthogonal experimental design. Compared with the baseline case, the maximum erosion rate of the five observation points in the optimized case decreases by the average of 33.74% with the maximum reduction of 36.32%, while the average erosion rate is reduced by the average of 37.57% and the maximum of 40.58%. The above results are contributed to the optimization of anti-erosion performance of high dust-containing flue gas waste heat utilization system and the development of efficient heat exchangers.