The present invention is a disposable saliva suction tube, which includes a layer of soft and hard plastic tube coated with a moisture-sensitive irreversible color coating, or a saliva suction mouth connected to the end of the soft and hard plastic tube, and the saliva suction tube The surface of the mouth is also coated with a layer of moisture-sensitive irreversible color paint； the color-changing suction tube constructed as described above, after contact with liquid, the part coated with the moisture-sensitive irreversible color paint will change its color, making the disposable The saliva can be discarded after use to avoid repeated use on others.本發明係為一次性吸唾管，其中包含一軟、硬式塑膠管一端表面塗佈一層感濕不可逆變色塗料，或在該軟、硬式塑膠管一端連接一吸唾嘴部，並在該吸唾嘴部表層亦塗佈一層感濕不可逆變色塗料；前述所構成之變色吸唾管，經接觸液體後，在塗佈有該感濕不可逆變色塗料的部份將改變其顏色，使該一次性吸唾管即能用後丟棄，避免重複使用在他人身上。
