The utility model relates to a telescopic belt type conveyor head transmission device and used for roadway transportation, which comprises a chassis and a transmission drum. A front strut is fixedly connected with the left side of the chassis. An extension frame is fixedly connected with the front strut. A rear strut is fixedly connected with the right side of the chassis. A rear horizontal beam is fixedly connected with the rear strut. A connecting beam is connected between the extension frame and the rear upper horizontal beam. The connecting beam, the rear upper horizontal beam and the extension frame are mutually connected through a connecting pin. A tripod-shaped drum fixing frame is corresponding fixedly connected with the front and the rear sides of the chassis. The connecting beam is connected with the upper end of the vertical frame body of each drum fixing frame. An angular bearing block is respectively fixedly connected with the two sides of left and right of the vertical frame body of each drum fixing frame. The transmission drum is respectively arranged between the angular bearing blocks of the left side and the angular bearing blocks of the right side. The connecting beam of the utility model can be individually opened and the transmission drum can be individually removed from the above, and the transmission drum can be easily repaired and replaced.