A comprehensive model with time limited wall reaction was developed for the simulation of complex gas particle molten slag three-phase reactions and flow processes in an entrained flow gasifier. Promotional conversion rate, wall reaction time and particle size/density evolution have been considered in the wall reaction model. In order to validate the proposed model, an industrial single swirling burner gasifier was simulated, and the gasifier performance, residual carbon ratio in the trapped particle and fly ash are compared with experimental measurements. The comparison results indicate that the proposed model has sufficient accuracy for entrained flow gasifier simulation. In a single swirling burner gasifier, approximately 55.4% of the coal particles fed from the swirling burner are trapped by the molten slag surface, and 22.5% of carbon in the trapped particles are converted during the wall reaction process. The detailed residence time of the trapped particle has been calculated; the average fly time of the particle before trapped is approximately 0.66s; and the average wall reaction time on the membrane wall is approximately 3.55s.