The impeller blades of ceramic slurry pumps are usually very thick for the purpose of prolonging the service life. In this paper, numerical simulations and wear test were conducted to investigate the influence of blade thickness on the solid–liquid two-phase flow and impeller wear in a ceramic centrifugal slurry pump. The wear test was conducted for CFD validation. The numerical results show that the incident angles of solid particles increase with increasing blade thickness, which results in larger wrap angles of the solid particle trajectories. The increasing wrap angles of the solid particle trajectories offset the region that the collisions between the blade pressure side and the solid particles side take place towards the impeller exit and lead to more impacts between the solid particles and the blade suction side. The numerical results are in good accordance with the wear pattern of the tested impellers, which demonstrates that the numerical method adopted in this paper is predictable in the abrasion of the impeller of a ceramic centrifugal slurry pump. The experimental results show that an increase in the blade thickness alleviates the abrasion of the leading edges and the pressure side of the impeller blades; however, it also aggravates the abrasion of the blade suction side and decreases the pump performance.