Provided is a cleaning device for cleaning optical lenses positioned in a tray. The cleaning device includes a supporting base for supporting the tray, two sliding members, a connecting plate, and a magnetic member. The supporting base includes a bottom plate and two parallel rails formed on a surface of the bottom plate. The sliding members are spatially corresponding to the rails, and each sliding member is slidably mounted on a corresponding one of the rails. The connecting plate is fixedly supported on the sliding members. The magnetic member is attached on a surface of the connecting plate facing toward the bottom plate.