Clean workbench capable of manually switching horizontal flow and vertical flow

The utility model discloses a clean bench capable of manually switching horizontal flow and vertical flow, which comprises a cabinet body and a fan system, the top and the rear part of the cabinet body are provided with inverted L-shaped chambers which are communicated with each other, the front part of the cabinet body is provided with clean chambers which are close to the inverted L-shaped chambers, the inverted L-shaped chambers are provided with air inlets, vertical air outlets and horizontal air outlets, and the fan system is connected with the cabinet body. The fan system is arranged in the inverted L-shaped cavity; the draught fan system comprises a draught fan body, an upper plenum chamber, a lower plenum chamber and a wind direction control device, the upper plenum chamber and the lower plenum chamber are arranged in an inverted-L shape, the upper plenum chamber is installed on the vertical air outlet and communicates with the top of the clean cavity, and the lower plenum chamber is installed on the