The utility model relates to a limiting device for outlet water temperature of a regulating and controlling valve for cold and hot water. The outer surface of a barrel neck of a box body of a regulating and controlling valve is provided with a groove, a convex bamboo shoot is upward extended and arranged on the upper end edge of the barrel neck, wherein, an inner hole of which is pivoted with a control rod device, and a convexly extended upward latch is arranged on the top surface of a sleeve seat of the control rod device. The surface of an inner hole of a temperature-limiting sleeve cap is provided with a groove corresponding to the groove of the barrel neck, the external surface is provided with an annular groove, the top surface of the temperature-limiting sleeve cap is provided with a rotating and limiting brim on which a hollow arc-shaped slot hole is arranged, and a marking knurling is arranged along the edge of the arc-shaped slot hole. The temperature-limiting sleeve cap is sheathed and closed on the barrel neck of the box body of the regulating and controlling valve, and the temperature-limiting sleeve cap can also be conveniently taken out to set limiting temperature of the hot water newly after the regulating and controlling valve is assembled with a tap.