<p>Based on flow decomposition, the integrals of the moment of momentum equation, flow equation and energy equation of regenerative hydrogen pumps are established. Among them, the inflow of impeller passage is expressed as the result of outflow and the forces in side channel. Additionally, a new design procedure is developed based on this flow model. Through this procedure, the main geometric parameters of flow passage parts can be obtained from the required pressure rise and flowrate. A parametric study of blade angle and blade number is carried out as a necessary part of the content completion for the design procedure. Based on the flow model, the simulation results of the flow field with different flowrates, rotational speeds, blade angles and blade numbers are analyzed; while the reasons for the variation of efficiency and pressure rise with these parameters are discussed. At the same time, the range of blade angles and blade numbers that are beneficial to performance is summarized.</p>