A method of displaying a dead zone of a construction machine, the method comprising: a) obtaining actual images with respect to omnidirectional views of a cabin in the construction machine photographed by a camera unit installed at the cabin, the actual images including front actual images photographed by a front camera, rear actual images photographed by a rear camera, left actual images photographed by a left camera, and right actual images photographed by a right camera; b) continuously matching actual images to continuously form virtual images by the front camera photographing a zone by a time interval by a rotation of the cabin to obtain two actual images showing the same zone and synthesizing the two actual images with each other to form a respective virtual image; c) measuring a rotation angle of a rotating working tool which is connected to the cabin and determining whether a dead zone is generated or not in accordance with the rotation angle of the rotating working tool and when the dead zone is generated, measuring a position of the dead zone, the dead zone being a zone positioned in front of a rotation direction of and screened by the working tool and not photographed by the camera unit; d) continuously storing virtual images corresponding to continuously changed dead zones in accordance with a continuous rotation of the rotating working tool; e) further comprising detecting a rotation of the cabin and measuring a present position of a present substitutive dead zone of the rotating working tool based on information with respect to a present position of the rotating working tool; f) selecting a virtual image among the stored virtual images, which corresponds to the present substitutive dead zone at the present position of the rotating working tool, based on the information; and g) displaying the selected virtual image on a displaying unit of the cabin. a) obtaining actual images with respect to omnidirectional views of a cabin in the construction machine photographed by a camera unit installed at the cabin, the actual images including front actual images photographed by a front camera, rear actual images photographed by a rear camera, left actual images photographed by a left camera, and right actual images photographed by a right camera; b) continuously matching actual images to continuously form virtual images by the front camera photographing a zone by a time interval by a rotation of the cabin to obtain two actual images showing the same zone and synthesizing the two actual images with each other to form a respective virtual image; c) measuring a rotation angle of a rotating working tool which is connected to the cabin and determining whether a dead zone is generated or not in accordance with the rotation angle of the rotating working tool and when the dead zone is generated, measuring a position of the dead zone, the dead zone being a zone positioned in front of a rotation direction of and screened by the working tool and not photographed by the camera unit; d) continuously storing virtual images corresponding to continuously changed dead zones in accordance with a continuous rotation of the rotating working tool; e) further comprising detecting a rotation of the cabin and measuring a present position of a present substitutive dead zone of the rotating working tool based on information with respect to a present position of the rotating working tool; f) selecting a virtual image among the stored virtual images, which corresponds to the present substitutive dead zone at the present position of the rotating working tool, based on the information; and g) displaying the selected virtual image on a displaying unit of the cabin.