Abstract: An analysis method of the aperture throttle based on turbulence state is presented in this paper. Three-layer velocity distribution expressions of the fluent in the turbulence state are obtained based on the boundary layer theory. The aperture flow equation for parallel-plates is deduced using the integration theorem and is verified by the comparison with the numerical solution of the CFD. The turbulence equations of the con-centric annular aperture are deduced based on this equation, and the influences of different physical parameters on the aperture pressure difference and the flow are analyzed, which can serve as the aperture throttle equation in the turbulence state for applications in engineer designs and for the improvement of the design accuracy of the throttle valve.