A dental drill head, constituted of a head housing, a wind wheel, and bearings, the head housing being constituted of a head housing cover and a head housing cavity, and the wind wheel being constituted of a wind wheel shaft and wind wheel blades. An anti-suck-back device is configured between the head housing cover and a wind wheel shaft end part to which the wind wheel shaft corresponds. The present invention, which adopts the aforementioned technical scheme, firstly makes it possible to reduce the intake in of contaminants when suck-back is taking place as the impeller is braked; and secondly, while there is still a positive pressure inside the head, the rubber head covering uses elastic force to brake the impeller and completely prevents the intake of contaminants. Moreover, the structure is simple and costs are low. Since the pressing area is reduced and the cavity is arranged between the rubber layers and the head covering, the teeth are less susceptible to touching the pressing portion. Even when the teeth do happen to touch the pressing portion, the cavity is so arranged that the teeth still will not touch the brake disc, thus avoiding any effect on the rotational speed; arranging the rubber ring inside the annular slot both prevents suck-back and automatically adjusts the dynamic balance, which is a double advantage and also lowers costs.