A method for constructing air-observed terrain data by using a rotary wing structure includes setting flight information including a photographing starting location and a photographing ending location on the basis of a flight route and a photographing location of the rotary wing structure; transmitting, to the rotary wing structure, the flight information so as to store the flight information in a flight control unit; capturing a ground image by a photographing unit of the rotary wing structure and storing the ground image in a storage unit when the rotary wing structure arrives at the photographing location; ending photographing and returning to the ground when the rotary wing structure arrives at the photographing ending location while repeatedly capturing a ground image; and constructing, by a computer in the control center, terrain data by using ground images stored in the storage unit.