Studying three-dimensional dynamic parameters of an insect flight requires reconstructing from 2D images, and two or more cameras are needed to capture images from different angles at the same time in the conventional method. A new method has been introduced. By adding four plane mirrors onto a high-speed camera, two different images are projected on the same frame, which is equivalent to that obtained using two cameras. Through calibrating the two optical paths, the external and intrinsic parameters can be computed, and then the three-dimensional information of fly's wings by using the mechanism of machine vision can be constructed. In contrast with conventional methods it is simple, inexpensive for three-dimensional reconstruction; moreover, there is no assumptions during reconstruction.