The invention provides a control system for a construction machine comprises a construction machine and a measuring instrument, wherein the construction machine comprises at least two targets, a tilt detecting component, a driving unit, a machine control unit and a machine communication unit, wherein the measuring instrument comprises a distance measuring unit, an optical axis deflecting unit for deflecting the optical axes, a projecting direction detecting unit for detecting a deflection angle and a deflecting direction and a measurement control unit for determining a measuring point and transmitting a measurement result, wherein the measurement control unit allows the distance measuring unit to alternately measure the targets and calculates a direction and front-back and left-right tilts of the construction machine based on three-dimensional positions of the targets and a detection result of the tilt detecting component, and the machine control unit controls the driving unit based on a calculation result.