To solve the problem of efficient heat dissipation of high-power miniaturized klystron collector under forced air cooling condition, this paper takes a high-power klystron as the research object, and introduces a design method of high-power and efficient air cooling collector system. ANSYS finite element software is used to simulate and calculate the forced air cooling heat dissipation characteristics of the collector. The effects of different cooling fin structures on the wind resistance and maximum temperature of the collector under non-uniform heat flux loading are analyzed and compared. The size and number of cooling fins are determined. To further improve the convective heat transfer effect of the air cooling collector system, the structure of the inlet of the collector is improved and the maximum temperature of the inner surface of the collector is reduced by 22 ℃. The calculation model of the wind resistance of the air cooling collector is used to verify the wind resistance. The difference between the simulation results and the theoretical value is 2.2%. Finally, the high-power klystron with the air cooling collector system is tested. The maximum temperature difference between the experimental and simulation results is 1.8%, which verifies the rationality and effectiveness of the design of the air cooling collector system.