The invention belongs to the technical field of CFD (computation fluid dynamics) calculation of high-performance computer systems, and particularly relates to a method for shortening CFD numerical-simulation calculating time on the basis of pre-operation. The method includes steps of (1) establishing a pre-operation test set; (2) defining a computer node set; (3) based on the established pre-operation test set, the method for shortening CFD numerical-simulation calculating time on the basis of pre-operation mainly includes three parts of (3.1) selecting test proportion conforming to CFD calculation requirements; (3.2) calculating the integral performance of various calculation node sets after pre-operation and selecting the set of the highest integral performance, namely the fastest operation for the proportion; (3.3) submitting the calculation node sets of the highest integral performance to specific CFD calculation tasks according to the step (3.2). By the method, CFD program operation time can be effectively shortened, execution efficiency of programs on the high-performance computers is improved.