A flow control valve includes: a valve body, a valve seat, a valve rod, a flow display device, a transparent cap and a turning knob. The flow display device is installed around a display section of the valve seat, includes a plurality of display straps observable from any direction via the transparent cap in order to determine the instant fluid flow rate regardless of whether the location of the flow control valve in an open and unobstructed space, or many obstacles in the wall, corner, or narrow space. The user can clearly see the flow display device from any angle so as to determine the real-time flow rate without deviation.