The invention provides a humidifier with a water filter device. The humidifier comprises a machine base, a water tank, an atomizer, a water adding device and a draught fan. The water tank comprises awater tank body and a water injection opening cover. The water injection opening cover is arranged on a water injection opening of a bottom plate of the water tank body for cooperation sealing. The humidifier further comprises the water filter device. The water filter device is arranged on a water outlet and extends towards the inner portion of the water tank body. The water filter device comprises a support, a water inlet connector, a filter element, a filter shell and a filter shell cover. An upper hole opening is formed in the top face of the support, and a lower hole opening is formed in the bottom face. Water outlet holes are formed in the circumferential outer wall of the support. The filter element is arranged in a body of the filter shell. The filter shell cover is used in cooperation with the filter shell for sealing the filter element. A grid type water outlet is formed in the bottom of the filter shell. The filter shell penetrates the support and is fixed to the upper hole opening. The water inlet connector is arranged in a cavity of the support. Due to the adoption of the structure, the humidifier has the function of filtering tap water injected in the water tank, cleanliness of water mist generated by the humidifier is improved, and indoor air is prevented from being contaminated.