The invention discloses a large-flow opening valve for agricultural irrigation. The large-flow opening valve comprises a valve body, the bottom of the valve body is provided with a base, the base is arranged on the valve body in a nested manner and is in close fit with the valve body to be fixed, the two ends of the side face of the valve body are provided with a water inlet and a water outlet correspondingly, the top of the valve body is provided with a locking cover, and the locking cover is arranged on the valve body in a nested manner and is fixedly connected with the valve body through bolts. The large-flow opening valve for the agricultural irrigation is compact and stable in structure, a structural design similar to an electromagnetic valve is utilized, a traditional built-in type rotary valve core replaces an up and down movable valve core, and the occupation space of the valve core inside the valve body is reduced, so that the flow in the valve body is increased; furthermore,the large-flow opening valve is convenient and flexible to use, safe and reliable to operate, high in stability and abrasive resistance and not prone to being damaged; and the opening valve is simpleand convenient to use, convenient and fast to assemble and disassemble and low in casting cost and has broad application prospects and practical advantages.