The utility model relates to a throttling device with an adjustable throttling ratio of a conical surface annular gap. The throttling device comprises a throttling device mounting body, a throttling device mounting sleeve arranged in the throttling device mounting body, and a throttling device body arranged in the throttling device mounting sleeve. A working region of the throttling device is formed by a conical gap between the rear end part of the throttling device body and a rear end cavity of the throttling device mounting sleeve; a through hole communicated with the working region is formed in the front end part of the throttling device body. A spring is arranged between the front end part of the throttling device body and a hole shoulder of the throttling device mounting sleeve; the position of the rear end part of the throttling device body on the rear end cavity of the throttling device mounting sleeve can be adjusted by an adjustable pressing head so as to adjust the throttling ratio. A whole static-pressure supporting system can use the throttling device with a single size and has the characteristics of good performances, compact structure, convenience for dismounting and mounting, low possibility of being blocked and the like.