An auxiliary chamber for inhaled-drugs includes a hollow tube body and a hollow side tube; and a unidirectional air valve which only allows air from an inlet flowing to an outlet end is located at the inlet end of the hollow tube body, wherein the outlet end of the hollow tube body is connected to an endotracheal tube. The hollow side tube connects with a lateral hole of the hollow tube body at one end, and a special universal adapter at the other end. The special universal adapter has a small through hole which is used to accommodate an inhaler therein to release inhaled drugs in the inhaler into the hollow tube body, and the inhaled drugs moves from the inlet end with air flow to the outlet end after entering the hollow tube body to help patients with respiratory failure take medicine.