A development method of B34 & B39 SAW dual filter for 5G communication carrier aggregation is present in this article, First, according to the product index, the design is determined by the topology design and the isolate of the signal of the dual channel filters; then the product is simulated and optimized through the coupling-of-mode model combined with the electromagnetic full-wave simulation, and finally the FEM/BEM is used to verify the performance of device, According to the comparison between the production and the simulation results, the graphs are in good agreement and fully meet the requirements of market, which proves the feasibility of the research method in this paper,