Three-way adjustable agricultural drainage system

The utility model relates to the field of agricultural farmland irrigation and drainage, and discloses a three-way type adjustable agricultural drainage system which comprises a system part and a device part, the system part comprises a drainage channel, and through holes are formed in the side wall of the drainage channel; the device part comprises a pipeline, a three-way joint and a plug cap; the pipeline comprises a water inlet pipeline I, a water inlet pipeline II and a water outlet pipeline; the three-way joint comprises a water inlet I, a water inlet II and a water outlet; one end of thefirst water inlet pipeline is connected with the first water inlet, the other end of the first water inlet pipeline is connected with the blocking cap, the second water inlet pipeline is connected with the second water inlet, one end of the water outlet pipeline is connected with the water outlet, and the other end of the water outlet pipeline is fixedly connected with a through hole of the drainage channel. The device p