Abstract: Existing single grade lithium bromide shield pump has the disadvantages of low efficiency and high energy consumption, so the research and development of two-stage miniature lithium bromide shield pump is important. Integrated motor and pump structure of two-stage miniature lithium bromide shield pump and its hydraulic components were designed. The design of hydraulic components included impeller design, combination design of radial diffuser and spiral volute, etc. FLUENT software was used to simulate the flow field of two-stage centrifugal pump. From the distribution of internal flow field, the performance values were predicted and compared with the design values when lithium bromide and water were respectively chosen as the medium. The prototype tests were carried out, and the results showed that the performance of two-stage miniature lithium bromide shield pump was better than the existing single stage one. The simulation values of the two-stage shield pump are close to the test values, which primarily validated that the simulation is credible and the design method is feasible.