An ultrasonic micron precision molding apparatus includes: an ultrasonic generating module, a tool and an amplitude transformer. The ultrasonic generating module provides ultrasonic frequency vibration. The tool is disposed below the ultrasonic generating module, and has a micron-level precision structure. The amplitude transformer is disposed between the ultrasonic generating module and the tool and has a first section and a second section, the first section is disposed at the junction of the amplitude transformer and the tool, and the distance between the second section and the tool is longer than the distance between the first section and the tool, wherein the width of the first section is greater than the width of the second section.