According to the current two-bench drilling and blasting construction methods of highway and railway tunnels， In order to meet the construction requirements of the cannon hole in the palm and system anchor rods and locking anchor rod holes of the hole wall， the MG-20S tunnel anchoring drill has been developed. The machine is three arms of curved arm amplitude mechanism， with all-round drilling attitude adjustment function， drilling construction can realize automatic / manual control dual mode， free switch， in the automatic control mode， only a button can control the rock drill rotation， impact and feed， and the drilling parameters can be adjusted in time according to the working conditions； using wireless remote control operation and manual operation of the cab with one key switch， only one person can operate to form a hole； it can realize the function of one-key to display car and one-key to collect the car， timely completion of anchor， drilling， injection process and loading， blasting， slag transport and other processes of efficient switching， make various processes professional， standardized. The industrial test shows that the drilling rig is reliable and effective， and all parameters， functions can meet the requirements of the construction technology of anchor and drill in two-bench of the tunnel.