The invention discloses a water and ink co-feeding device of a commercial printing
machine. The water and ink co-feeding device comprises a rubber roller, a plate cylinder, an ink vibrator and a dampening vibrator which are bridged between wallboards at the two sides of the printing
machine; the water and ink co-feeding device further comprises an inking roller matched with the ink vibrator, an inking roller and ink vibrator pressure adjusting mechanism, an inking roller and plate cylinder
clutch mechanism, an inking roller and plate
cylinder pressure adjusting mechanism, a form dampening roller matched with the dampening vibrator, a form dampening roller and dampening vibrator pressure adjusting mechanism, a form dampening roller and plate cylinder
clutch mechanism, a form dampening roller and plate
cylinder pressure adjusting mechanism, a water and ink co-feeding roller, a water and ink co-feeding roller and inking roller pressure adjusting mechanism and a water and ink co-feeding roller and form dampening roller pressure adjusting mechanism; and the water and ink co-feeding roller is arranged between the form dampening roller and the inking roller and is simultaneously engaged and disengaged with the inking roller and the form dampening roller through the water and ink co-feeding roller
clutch mechanism. According to the water and ink co-feeding device, the printing color can be brighter, and the quality of a finished product printed on paper with poor water absorption is greatly improved.