An air purifier comprising a main unit, a base assembly below the main unit, a filter screen assembly inside the main unit and an air supply device above the filter screen assembly, wherein the base assembly comprises a carrier part on which the filter screen assembly is provided and a lifting part that is located below the carrier part and abuts the carrier part. The lifting part comprises a pull-push part and a lifting assembly configured such that when the pull-push part makes a translation in a first direction, the lifting assembly controls the carrier part to descend and separate the filter screen assembly from the air supply device, and when the pull-push part makes a translation in a second direction opposite the first direction, the lifting assembly controls the carrier part to rise and achieve a sealed connection between the filter screen assembly and the air supply device.