The invention discloses a fiber recycling and treating device and method of used clothes. The fiber recycling and treating device comprises a tank and a control device, a water incoming pipe, a waterdraining pipe, an air exhausting pipe, an agent adding pipe and a discharging pipe are arranged on the tank, a fetching hole is formed in the side face of the tank, a detachable observation window ismounted on the fetching hole, a pump is arranged on the side face of the tank, a carrying plate is arranged in the tank, an annular air cavity is formed inside the carrying plate, an air exhausting nozzle of the pump is connected with the air exhausting pipe which sequentially penetrates the tank and the carrying plate, the tail end of the air exhausting pipe is positioned in the annular air cavity, the air exhausting pipe is communicated with the annular air cavity, more than one elbow and a mounting hole are arranged on the carrying plate, the elbows are obliquely arranged, a first electromagnetic valve is arranged in each elbow, and the elbows are distributed in an annular array by taking the mounting hole as a central point. By the fiber recycling and treating device and method, cellosilk in the tank can be extracted quickly.