The invention discloses an ultrasonic wave cleaner for a coating of an optical lens and a treatment method thereof, which belong to the fields of metal surface treatment technology, vacuum coating technology and optical technology. The ultrasonic wave cleaner is characterized by performing ultrasonic alkali cleaning, pure water rinsing and ultrasonic pure water rinsing on the optical lens in cleaning medium under the condition of pendular motion respectively, slowly and perpendicularly lifting the optical lens or ensuring that a liquid slowly descends to break away from a workpiece when running water is circularly filtered, and using hot air to dry the optical lens under quiescent conditions. A structure of the ultrasonic wave cleaner is that: a conveyer is provided with traveling girders, the girders are provided with grab hooks, and the hooks are suspended with washing baskets; and different working procedures are finished by different devices, namely a liquid tank body is matched with a pendulous device, a dehydration device and a drying device to finish respective working procedures. The ultrasonic wave cleaner and the method have the advantages that the ultrasonic wave cleaner and the method do not use inflammable, explosive and toxic organic solvents to wash, reduce energy consumption, avoid the air pollution in workshops, can effectively improve the cleanliness of products, and ensure that the adhesive force of the coating of the optical lens is remarkably improved.