The jet pump is widely applied to industry fields. The nozzle, throat tube, and diffusion tube of the jet pump is variable to meet different working conditions. Parameterization design of a jet pump can be used to design the throat tube and diffusion tube via a given nozzle diameter and sectional area ratio. The virtual assembly of the jet pump, which consists of upper body, pump core, under body, and pump shell, is used to verify the fitting allowance of parts. The result provides an anticipated inspection for manufacture and improves the design efficiency.