Disclosed is an air purifier, which comprises a shell with an air inlet and an air outlet, an ecological purification system with a flowerpot assembly, a microorganism box and a water tank arranged in sequence, a filtering system, and a control system for carrying out control. The water of the ecological purification system flows through the filtering system to bring dust and VOCs adsorbed by the filtering system into the ecological purification system for purification. The flowerpot assembly comprises a flowerpot. The water of the water tank enters the flowerpot via a water inlet, and when the water level is higher than a water outlet, the water flows through the microorganism box and then enters the water tank, so as to form the water circulation. The air purifier is simple in structure, easy to operate and low in cost, and has a high purification efficiency for air pollutants, especially VOCs.