Abstract: The smoke simulation plays an important role in the virtual simulation of a large-scale complicated environment such as a battlefield,where real-time simulation is hardly achieved due to the complication and intensive computation in solving the Navier-Stokes equation.The MacCormack method is proposed to solving the advection item of Navier-Stokes.By the method,first,the forward advection operator is applied to get the forward smoke velocity,and then,the backward advection operator is applied to get the backward smoke velocity.Finally,the calculated forward advection data is corrected according to the estimated error.By the new method,the processing steps in the method of back and forth error compensation and correction during solving the advection item can be substantially reduced.Experimental results show that the optimization can be applied to obtain better visual effects,and achieve real-time simulation through reduction of the computing time in the simulation.