Objective To optimize the structure of gas-phase rotary heat exchanger and address low heat transfer efficiency of gas-phase rotary heat exchanger with single-blade shell-side structure.Methods The performance of three kinds of shell-side heat exchangers is analyzed by establishing a simplified model and computational fluid dynamics (CFD) method. Taking the shell-side pressure drop and convective heat transfer coefficient as the test indexes, this study explores the influence of main parameters such as the number of working circles, blade height, and blade width on the shell-side pressure drop and convective heat transfer coefficient and conducts optimization and verification.Results The overall performance of the six-blade heat exchanger is better, with the shell-side pressure drop reduced by 7%~8% and the convective heat transfer coefficient increased by 8%~10%. In the case of 3 working circles, the blade height of 45.05 mm, and the blade width of 4.79 mm, the minimum shell-side pressure drop of the six-blade heat exchanger is 6.95 kPa, which is 15%~21% lower than that before optimization. The maximum convective heat transfer coefficient is 183.35 W/(m²·K), which is 10%~12% higher than that before optimization. The error between the simulated value and the experimental value of shell-side pressure drop is ≤6%, and the error between those of the convective heat transfer coefficient is ≤5%. The optimization results are reliable.Conclusion With the optimized shell-side structure, the gas-phase heat exchanger has good heat transfer performance.