A positioning assist device for drilling multiple dental implant holes is disclosed, which includes a main arm unit and an extension arm unit. The main arm unit has an arm body with two opposing ends, in which a reference shaft is pivoted on a first end, and an extension arm unit is pivoted on a second end via a connecting shaft. A drill-guiding portion having a drill-guiding hole is disposed on an external end portion of the second connecting head. The reference shaft is inserted into a first dental implant hole through an axis hole of the first end. The positions and angles of the drill-guiding hole of the extension arm unit can be adjusted to reach other dental implant holes by pivoting on the reference shaft and the connecting shaft, so as to lead a driller to drill other dental implant holes precisely according to the drill-guiding hole.
