In fluid dynamics optimization, modern high-temperature oil pumps utilize 3D simulation design technology. Through ANSYS Fluent, multiphase flow simulations are conducted to calculate the turbulent state of the medium between the gear slots, optimizing the involute gear profile parameters, thereby increasing the volumetric efficiency to over 92%. Certain special pump models are also equipped with variable pitch gear structures, employing a large pitch design at the suction end to reduce cavitation effects, while a tapered pitch is used at the discharge end to maintain stable pressure pulsations, keeping the outlet pressure fluctuations within ±1.5%.