Drilling machine electric drill provided with positioning device

The invention discloses a drilling machine electric drill provided with a positioning device. A vertical sliding rail is arranged in the electric drill. A sliding block is arranged on the vertical sliding rail in a matched mode. A drill bit of the electric drill is fixed to the sliding block and is in sliding connection with the vertical sliding rail. Engaging teeth are arranged on the drill bit of the electric drill. The positioning device comprises a pin column, a limiting block and a spanner. The two ends of the pin column are hinged to the two sides of a shell of the electric drill, and the top end of the pin column stretches out. An outer spline matched with the engaging teeth is arranged in the middle of the pin column. The pin column is engaged with the drill bit of the electric drill through the outer spline. A limiting rod is arranged at the stretching-out end of the pin column, and the limiting block is located on the lower portion of the stretching-out end of the pin column. A U-shaped groove corre