The invention discloses an air-drying device for plastic braces, which comprises a conveying unit, an air-drying unit, and a gas-liquid separation unit. The air-drying unit includes a water receiving tray and a fan connected to the bottom of the water receiving tray through an air pipe. The conveying unit includes a set The two sets of conveying rollers on the upper end of the water receiving tray, the cover plate located above the water receiving tray, the plastic stays are moved and tensioned between the two sets of conveying rollers and the cover plate, and the gas-liquid separation unit includes a A separation box with a separation chamber inside. The lower part of the separation box has a drain port and the upper part has an exhaust port. A gas-liquid separation channel is formed between the air outlet of the fan and the exhaust port. The cover plate is hingedly installed on the upper part of the water tray to ensure the wind pressure of the air inlet when the fan is working. The fan sucks away the moisture on the plastic braces in real time, and the air flow with water enters the gas-liquid separation unit from the air outlet. After separation, the gas flows from the exhaust port. Drain, the water is discharged from the drain port, the structure is simple, compact, simple and beautiful, the work is reliable, and the work efficiency is effectively improved.