Optimized design method of multistage depressurization sleeve

The invention discloses an optimized design method of a multistage depressurization sleeve; wall thickness of a sleeve barrel worked out according to a provided sleeve wall thickness computation method is gradually reduced from outside to inside. Gaps among multiple stages of sleeves worked out by a provided multistage depressurization sleeve gap computation method are gradually narrowed along with the traveling direction of fluid. The invention provides a reasonable method for computing depressurization stage numbers, sleeve barrel wall thickness and gaps among the stages, and the multistage depressurization sleeve designed according to the above method has the advantages of good anti-cavitation and low noise.