The invention provides an evaporative humidifier. The evaporative humidifier mainly comprises a bottom shell, a fan, a water tank, a humidifying net and an upper cover, wherein the fan and the water tank are connected with the bottom shell, the upper cover is detachably arranged on the water tank, a water storage cavity is formed in the water tank, the humidifying net is inserted into the water storage cavity, the water tank further comprises a first air inlet channel, a second air inlet channel and an air outlet channel, a first air inlet of the first air inlet channel is located on the uppercover, a second air inlet of the second air inlet channel is located on the top wall of the water storage cavity, an air outlet of the air outlet channel is located on the side, close to the upper cover, of the outer side wall of the water tank, the second air inlet channel correspondingly communicates with the first air inlet channel and the air outlet channel, and the fan can be used for exchanging first gas in the first air inlet channel and the second air inlet channel, and discharging exchanged second gas through the air outlet of the air outlet channel. According to the evaporative humidifier, the water tank and the air channels are of an integrated forming structure, the structure is simple, the air inlet and outlet efficiency, the noise is low, water adding is convenient, and theuse is safe.