A control structure capable of adjusting water volume and controlling water supply comprising: a fixer comprising a retaining rib arranged around an inner wall of the fixer ; a valve stem comprising: an inlet defined in the valve stem , a fixing rib arranged on a first end of the valve stem , an opening formed on a second end of the valve stem , the opening formed on the second end of the valve stem communicating with the inlet , and a guiding column extending outward from a side of the opening , the guiding column having a diameter less than a diameter of the opening and having a seal ring fitted thereon; a body comprising: a water outflow segment formed on a first end of the body and configured to connect with a watering tool, and an accommodation groove configured to accommodate the fixer and the valve stem , the valve stem communicating with the water outflow segment of the body ; a controller for coupling with a water supply pipe, the controller comprising: a screwing section arranged on an outer wall of the controller , an inflow aperture formed on a middle section of an inner wall of the controller , and a shoulder formed beside the inflow aperture ; and an adjuster comprising a threaded orifice screwing with the screwing section of the controller and fitting with the guiding column , wherein the fixing rib of the valve stem retains with the retaining rib of the fixer so as to limit a rotation of the adjuster along the body . a fixer comprising a retaining rib arranged around an inner wall of the fixer ; a valve stem comprising: an inlet defined in the valve stem , a fixing rib arranged on a first end of the valve stem , an opening formed on a second end of the valve stem , the opening formed on the second end of the valve stem communicating with the inlet , and a guiding column extending outward from a side of the opening , the guiding column having a diameter less than a diameter of the opening and having a seal ring fitted thereon; an inlet defined in the valve stem , a fixing rib arranged on a first end of the valve stem , an opening formed on a second end of the valve stem , the opening formed on the second end of the valve stem communicating with the inlet , and a guiding column extending outward from a side of the opening , the guiding column having a diameter less than a diameter of the opening and having a seal ring fitted thereon; a body comprising: a water outflow segment formed on a first end of the body and configured to connect with a watering tool, and an accommodation groove configured to accommodate the fixer and the valve stem , the valve stem communicating with the water outflow segment of the body ; a water outflow segment formed on a first end of the body and configured to connect with a watering tool, and an accommodation groove configured to accommodate the fixer and the valve stem , the valve stem communicating with the water outflow segment of the body ; a controller for coupling with a water supply pipe, the controller comprising: a screwing section arranged on an outer wall of the controller , an inflow aperture formed on a middle section of an inner wall of the controller , and a shoulder formed beside the inflow aperture ; and a screwing section arranged on an outer wall of the controller , an inflow aperture formed on a middle section of an inner wall of the controller , and a shoulder formed beside the inflow aperture ; and an adjuster comprising a threaded orifice screwing with the screwing section of the controller and fitting with the guiding column , wherein the fixing rib of the valve stem retains with the retaining rib of the fixer so as to limit a rotation of the adjuster along the body . <EOS>