The invention discloses an OpenMP/MPI hybrid programming-based communication optimization method of a CFD simulation program. The method specifically includes the following steps: carrying out area decomposition on a calculation domain according to communication loads and calculation loads to divide the same into multiple sub-domains on which parallel solving can be carried out; determining network topology relationships among all grid blocks according to setting situations of {processes and thread groups}, and creating and initializing MPI persistence communication relationships among the processes; after calculation advancing which is independent among threads ends, activating MPI channels among the processes for message communication, using shared memory at the same time to communicatein the thread groups to realize boundary data exchange among the grid blocks; and calculating residuals in the thread groups, collecting a maximum residual among the processes, if the maximum residualstill does not meet a convergence condition, returning to the grid advancing step for iteration, and otherwise, ending parallel calculation. Therefore, parallel efficiency of the CFD simulation program can be effectively improved.