Abstract: Some embodiments of the present disclosure provide a water softener, a humidifier base, and a humidifier. The water softener includes: a housing internally provided with a resin cavity and sequentially provided with a water inlet and a water outlet along a flowing direction of a water flow; a snap provided on the housing; and a positioning column provided on the end of the housing corresponding to the water inlet and extending toward a direction away from the housing. By providing the snap and the positioning column, when the water softener needs to be assembled, it is merely required to mount the snap and the positioning column to the corresponding parts of one humidifier; in this case, a water flow will enter the water softener through the water inlet to implement a subsequent water softening operation.