Variable air volume adjusting method and device for exhaust hood of laboratory

The invention discloses a variable air volume adjusting method and device for an exhaust hood of a laboratory. The adjusting method comprises the following steps: S1, an air volume Q1, which needs tobe exhausted from a ventilation pipe in the process in which a fully closed window of the exhaust hood is fully opened, is calculated, and a target air volume curve is drawn; S2, an exhaust valve is selected according to the target air volume curve and an effective stroke range of a valve element assembly of the exhaust valve when the exhaust valve is arranged; S3, an effective stroke L1 in the process in which the fully closed window of the exhaust hood is fully opened, an effective stroke L2 of the valve element assembly in the process in which the fully closed exhaust valve is fully opened,and a register ratio N are calculated; S4, the window of the exhaust hood moves to drive a linkage mechanism to move; and S5, the linkage mechanism drives the valve element assembly of the exhaust valve to move, so that a ven