An active measurement system was put up to measure the servo accuracy of a servo stable platform. On the basis of the system, a new pose estimation method of monocular vision was proposed according to the parallel theory. First, the hardware composition and measuring principle of the system were introduced and its resolution was analyzed. The calculation principle and calculation process of the world coordinates of laser points were given. Then, from the freedom of a parallel mechanism, the visual measurement system was transformed into a parallel mechanism equivalently, and the pose estimation problem was transformed into a forward solution problem of parallel mechanism. Furthermore, the kinematics influence coefficient of the parallel mechanism was used to estimate the pose of the system. Instead of complex derivations, the kinematics influence coefficient could be obtained directly. The simulation and experimental results show that the orientation measurement accuracy of the system is ± 0.05 °,which concludes that the method has a rapid and stable convergence for the design requirements of the system.