The invention discloses an ultrasonic welding device for an automobile sun shield clad with non-woven fabric through welding. The ultrasonic welding device comprises a base, a main support, a first ultrasonic welding unit group and a second ultrasonic welding unit group. A guide way, a first sensing switch and a second sensing switch are arranged on the base; a screw rod with one end being connected with a servo motor is arranged in the middle of the guide way; a screw rod nut fixing seat is arranged on the screw rod; a movable lower mold fixing plate is arranged on the guide way; the main support is fixed to the base; and the first ultrasonic welding unit group and the second ultrasonic welding unit group which are identically composed and structured are arranged on the main support in parallel. The obtained ultrasonic welding device for the automobile sun shield clad with the non-woven fabric through welding has technical effects that the non-woven fabric and the automobile sun shield can be efficiently ultrasonically welded with low energy consumption, the welding effect is good, and the whole device is simple in structure and convenient to operate.