A horizontal drilling machine with an impact device, including a support frame, an armored cable, a cable-straightening mechanism, a cable-feeding mechanism, a power head, a drill pipe, a rotating chuck, a damper, a fishing device with the impact device, a core tube and a thrust cylinder. One end of the thrust cylinder is hinged with the support frame, and the other end of the thrust cylinder is connected to the power head. The power head is arranged on a slid rail of the support frame. An active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to a control system, and the other end is connected to the fishing device in the drill pipe. A fishing head of the fishing device is connected to a spearhead of the core tube.