The invention discloses a percussion drill auxiliary device. The percussion drill auxiliary device comprises a base, and is characterized in that support rods are symmetrically arranged above the base; a cross bar is arranged between the support rods; a percussion drill positioning device is arranged in front of the cross bar; a moving device capable of driving the positioning device to forwards move is arranged above the cross bar; a cleaning device is arranged below the cross bar; a control induction device capable of controlling the drilling depth is arranged on one side of the auxiliary positioning device; a rotating device capable of driving the auxiliary positioning device to rotate is arranged at one end of the cross bar; and an adjusting device capable of driving the positioning device to adjust the height is arranged on one side of the cross bar. The percussion drill auxiliary device is simple in structure and convenient to use, realizes positioned drilling through hand adjustment of the percussion drill positioning device, uses the rotating device for driving the positioning device to overturn to realize drilling of walls and ceilings, and then, uses the control moving device and the control induction device for realizing control of the drilling depths; and the cleaning device can realize the dust cleaning work, so that the multifunctional percussion drill auxiliary device can meet various people use demands.