Abstract: A device for controlling incoming/outgoing of water flow of a sprinkler, comprising a control tube, a control pin, a pushing block, a frame member and a spring, wherein the control tube has a water incoming end and a water outgoing end and an outer surface of the control tube is formed with a rectangular recess. A pin chamber is disposed at a middle section of the recess and extends downward therefrom. The pin chamber having a first side wall formed with a water inlet, a second side wall formed with a water outlet, and a bottom wall formed with a communicating hole. The control pin has a substantially semispherical head section and three projecting ring sections. Each ring section of the control pin is formed with an annular groove receiving a sealing ring. The pushing block has a bottom face formed with a depression, two lateral projecting ribs, and an inclined wall located in the depression. The frame member is formed with an elliptic hole and a rectangular peripheral groove surrounding the elliptic hole.