A new method of landing position and attitude measurement of UAV using only one runway image, which is proved applicable to such circumstance as UAV approaching to the ground while the runway width is known, is proposed in this paper. Firstly, the relation between the attitude and the vanishing point of runway was analyzed. Then, the collinearity equation was transformed by the runway line and the image line equations coefficients. Furthermore, the position along runway and the bank angle was simplified on the basis of the reasonable assumption. In so doing, the landing position and attitude of UAV was calculated by previous relations. Simulate experiment results show that the new way is easy to realize and can satisfy the application requirement of autonomous landing.