In order to develop a three-screw pump for water-based flame retardant hydraulic fluid, the viscosity-temperature characteristic curve of water-glycol flame retardant hydraulic fluid is measured, a three-dimensional(3D) model of three-screw pump is established, and Computational Fluid Dynamics (CFD) numerical analysis and experimental verification is carried out. In the CFD simulation calculation, in order to avoid the excessive mesh volume or negative volume, the actual meshing gap could not be guaranteed. The SCORG software was used to divide the common structure grid of the pump inner channel and combined with Pumplinx software for data post-processing. The research shows that the simulation results of the dynamic numerical simulation method are in good agreement with the experimental results, and the characteristics of the hydraulic fluid and water-based hydraulic fluid transfer are compared and analyzed. The relationship figure between the main rod torque and the pump leakage with varying temperature of the hydraulic medium is obtained. Water-based hydraulic liquid phase is more prone to cavitation than oil, cavitation mainly occurs in the pump inlet cavity, cavitation phenomenon gradually decreases as the seal chamber pressure rises, and the higher is the pump speed, the larger is the cavitation gas volume fraction. The smaller the pump outlet pressure is, the larger the cavitation gas volume fraction is. As the outlet pressure increases, the effect of the rotational speed on the cavitation gas volume fraction is less obvious. The water-based liquid three-screw pump is more prone to oil film damage during operation, and the maximum stress of the oil film is 4.369 9 MPa through fluid-solid coupling analysis.