The invention discloses an artificial wetland weed suppression and water distribution device. A weed suppression and water distribution plate is provided with a plurality of water distribution units and ventilation units of the same structure. The water distribution units are connected with the ventilation units. Each water distribution unit is provided with a water distribution head. Each ventilation unit is provided with a ventilation head. The water distribution heads are arranged downwards. The ventilation heads are arranged upwards. The joints of the water distribution units and the ventilation units form shading and weed suppression components. A water distribution perforated pipe comprises a water distribution hole for guiding water into the weed suppression and water distribution plate. According to the artificial wetland weed suppression and water distribution device and method, the weed suppression components are composed of the water distribution units and the ventilation units; due to water cross flow and the multi-point structure of the water distribution device, water oxygenation and uniform water distribution are achieved, soil has the good ventilation, weed growth is prevented, and deadwood and garbage are isolated; accordingly, the wetland treatment efficiency is improved, and operation and management are easy and feasible; in addition, the weed suppression and water distribution method can reduce the number of water distribution perforated pipes and the number of perforated holes.