Abstract: Aiming at the problem of long time and slow positioning speed when the digital zenith camera was in precise leveling state for astronomical positioning, based on the principle of positioning the digital zenith camera, the correction model of the inclination angle was established by the direction cosine matrix transformation principle, the positioning method after the correction of the tilt angle was analyzed and deduced, and the two kinds of localization algorithms of the tangent plane and the spherical triangle of the digital zenith were improved, achieved the positioning of equipment without fine leveling, speeded up the positioning speed of the purpose. The accuracy of the two types of positioning algorithms in the tilted state was compared by experiment. Experiments show that the positioning accuracy of the spherical triangle method is relatively high, and the calculation accuracy of the latitude and longitude can reach 0.5 or less.