Operating/controlling structure of detergent-mixable sprinkling gun, including a gun body, a sprinkling head, a connecting body connected between the gun body and the sprinkling head, a valve seat, an operating/controlling member, a locking bolt and a detergent barrel. The water flows into the gun body and then flows out from the sprinkling head. The connecting body has a seat body formed with a seat tube and a seat sink connected therewith by a stop board. A spring pin is fitted in the seat sink. The seat tube communicates with an outlet and an inlet. The outlet and inlet respectively communicate with two communicating holes. The valve seat has a circular boss. A valve shaft upward extends from the circular boss. The center of the top of the valve shaft is formed with a through hole. A semicircle of the top of the valve shaft is formed with several engaging cuts. A gate body is disposed between the valve shaft and the circular boss. The circumference of body of the valve seat is formed with two groups of through holes with different sizes opposite to each other. The operating/controlling member is cap-like. The bottom of the operating/controlling member is formed with a fitting post. The inner circumference of the fitting post is formed with several ribs. The bottom face of the operating/controlling member is formed with several locating dents. A guiding groove is formed on the bottom face and adjacent to the locating dents. A stop block is formed on the bottom face. The detergent barrel is screwed into the inner thread of the seat body.