Drug application device for seawater net cage cultured fishes and drug application method

The invention relates to a drug application device for seawater net cage cultured fishes. The device comprises a controller, an upper frame, a lower frame provided with a bottom net, side nets connected with the upper frame and the lower frame respectively, a floating plate arranged in the middle of the upper frame and provided with a mounting cavity at the upper end, a connecting piece connected with the floating plate and the upper frame respectively, a through hole formed in the bottom face of the mounting cavity and communicated with the lower end of the mounting cavity, an air compressor connected with the upper end of the floating plate, a drug tank provided with a sealing cover communicated with an outlet of the air compressor, a drug discharging pipe mounted in the mounting cavity and with the upper end communicated with the lower end of the drug tank, a rotating connector with the upper end communicated with the lower end of the drug discharging pipe, a rotating driving device, a vertical drug distribution pipe, an adjustable bubble curtain net building device and a drug recycling device. The lower end of the vertical drug distribution pipe is provided with a drug distribution disc, and the upper end of the vertical drug distribution pipe penetrates through the through hole and is communicated with the lower end of the rotating connector. The adjustable bubble curtain net building device communicates with the outlet of the air compressor. The drug application device for the seawater net cage cultured fishes is good in fish disease treatment effect.