Diffuser

The invention discloses a diffuser. The diffuser comprises a hub, main blades and splitter blades. In a flow channel of the diffuser, the main blades and the splitter blades are alternately arranged and evenly distributed in the circumferential direction, a main airflow channel is formed by every two adjacent main blades, and the splitter blades divide the main airflow channel into two parts on the rear section of the main airflow channel. The outer side wall of the hub is provided with a radial surface, a turning surface and an axial surface; the main blade comprises a radial diffusion section, a turning section and an axial diffusion section, the radial diffusion section is connected with the radial surface, the turning section is connected with the turning surface, and the axial diffusion section is connected with the axial surface; and the front edges of the splitter blades are positioned on the turning surface and the rear edges are positioned on the axial surface. The main blade adopts an integrated des