Abstract:The thermal stability of structural surfaces is one of the important indicators for spacecraft structural design, which plays an important role in achieving the functionality and performance of spacecraft in the vacuum and low temperature environment of orbit. To ensure the correctness of structural thermal stability design, it is necessary to conduct thermal stability testing tests in space environmental on the ground surface of spacecraft structures. The research on the high-precision and high-frequency thermal stability deformation testing requirements of large-scale structures was conducted. Using optical photography in-situ deformation measurement technology, a multi camera fusion measurement system architecture and measurement method were designed, effectively ensuring the construction of the optimal deformation measurement field for large structures. Through the intelligent synchronous control design of the system electromechanical and image acquisition devices, automatic matching of spatial position attributes of image data was achieved. Through verification of the experimental system, the results showed that the system can meet the transient and high-precision structural deformation measurement of no less than 4 meters in vacuum and low-temperature environments. The minimum measurement period can reach 90 seconds, and the unidirectional measurement accuracy is better than 28μm. The testing process runs stably and reliably.