In recent years, in the aerospace field, higher requirements have been put forward for the position and pose measurement tasks such as engines. Computer vision technology is the key technology to achieve the target measurement tasks. Rocket engine pose measurement provides technical support for engine pose control strategy optimization. Based on the principle of monocular vision, this article designs a measurement system with strong stability and high accuracy for launch vehicle engines, and verifies the effectiveness of the measurement system through two sets of simulation experiments. In terms of image preprocessing, the noise reduction effects of spatial filtering and wavelet transform were compared, and a preprocessing method combining wavelet transform and image enhancement was designed; In terms of feature extraction, improvements have been made to the traditional Accelerated Feature Segmentation Test (FAST) algorithm to reduce the impact of lighting on feature point extraction under different postures, while retaining the advantage of high-precision measurement algorithms under point features; In terms of pose measurement, the centroid and translation vector pre pose iterative optimization algorithm is adopted, which greatly reduces the computational complexity in the pose calculation iteration process and improves the speed of spatial target pose calculation. © 2023 SPIE.