Numerical simulations were conducted to investigate the flow of a typical layout of dorsal binary curved compression inlet at different angles of attack. The results show that the flow coefficient of the inlet and the total pressure recovery coefficient of the throat decrease simultaneously with the increase of the angle of attack, and the flow coefficient decreases by 24.4% and the total pressure recovery coefficient decreases by 14.8% when the angle of attack increases from 0° to 10°. The boundary layer diverter can effectively improve the flow coefficient and total pressure recovery coefficient of the inlet, in which the flow coefficient increased by about 4%, and the total pressure recovery coefficient of the throat increased by about 0.02. The analysis of the study shows that, with the increase of the angle of attack of the flight, the masking effect of the forebody on the dorsal inlet induces the appearance of the forebody expansion wave, which causes the acceleration of the airflow in front of the inlet. The higher Mach number and uneven distribution in front of the inlet are the main reasons for the simultaneous decrease of the flow coefficient and the total pressure recovery coefficient. Accordingly, a theoretical model of the flow characteristics of the forebody/inlet for this type of dorsal layout is established, which reveals the linear correlation between the Mach number in front of the inlet and the angle of attack, which can be used to predict the flow characteristics of the inlet accordingly. By changing the relative position of the inlet along the flow direction in the forebody, the influence of the boundary layer on the inlet flow can be improved, and the flow coefficient and total pressure recovery coefficient can be enhanced, but the enhancement is limited due to the fact that the Mach number in front of the inlet is still high and unevenly distributed.