A flow control valve, includes a valve body component, a valve seat component and a valve core component, wherein the valve seat component includes a sealing ring, a first annular protruding portion and a second annular protruding portion; the valve core component includes a valve core including a lower section portion; when the valve core abuts against the sealing ring; the first annular protruding portion includes a first inner wall portion; the second annular protruding portion includes a first outer wall portion; and when the valve core abuts against the sealing ring, the minimum inner diameter of the first inner wall portion is D1, the maximum outer diameter of the first outer wall portion is D2, the minimum inner diameter of the lower end portion is D3, and the maximum outer diameter of the lower end portion is D4, then D3−D2