As a new type of multi-stage high-performance regulating valve, the labyrinth disc regulating valve takes advantage of the labyrinth channel on the sleeve disc to dissipate the high-pressure differential energy into the multi-stage throttling flow resistance. It can effectively prevent the failure problems such as erosion, cavitation, and noise caused by extreme working conditions such as the high-pressure differential, high-speed flow, and high temperature. In order to study the flow characteristics of the fluid inside a new type of labyrinth disc-type regulating valve in the thermal power process, an experiment on the pressure reduction characteristics of a double-entrance labyrinth flow channel was carried out. Firstly, an experimental device was designed and built, and then the pressure drop values of each horizontal flow channel were measured and compared with the numerical simulation results to verify the accuracy of the numerical model. Aiming at the actual working conditions of the labyrinth disc regulating valve in thermal power generation applications, the Realizable k-- turbulence model and the mixture multiphase flow model are combined with the Zwart-Gerber-Belamri cavitation model to clarify the flow characteristics and cavitation of the incompressible medium water in the labyrinth flow channel inside the labyrinth disc regulating valve and the flow characteristics of a double-entrance labyrinth flow channel under different opening degrees.