The overall manufacture of the small-diameter variable-section composite air inlet is difficult, and the small size of the inner cavity makes it impossible to carry out surface treatment. Based on this, this paper proposed a manufacturing method to realize the integration of structure and function.The block and combined structure design is adopted, then the skin parts with uniform thickness (surface waviness not exceeding 0.5 mm) and small deformation are formed under the process control. To solve the problem of seam level difference between segmented skins, the synergistic method of flange edge connection and fixed connection with plate is adopted. The composite air inlet that meet the design and usage requirements has been successfully manufactured.