A kind of drill bit of dental handpiece, including: one first body of rod, bottom end connect what dental handpiece； One second body of rod, bottom end sets first body of rod of what top, and top is bore portion； One connection structure links together first, second body of rod, and internal with an accommodating space； And a spring, if the accommodating space of what connection structure, two ends are pushed up respectively to be set between first, second body of rod of what； Drill object Hou in bore portion, spring can open second body of rod, use achieve the purpose that drill object Hou be automatically stopped bore portion rotation.一種牙科手機之鑽頭，其中包括：一第一桿體，底端連接於牙科手機；一第二桿體，底端設於第一桿體頂端，且頂端為鑽孔部；一連接結構，將第一、第二桿體連接在一起，且內部具有一容置空間；以及一彈簧，設於連接結構之容置空間，二端分別頂設於第一、第二桿體之間；在鑽孔部鑚穿目標物後，彈簧可頂開第二桿體，藉以達到在鑚穿目標物後自動停止鑽孔部轉動的目的。
