###### Abstract  
The optical axis angle fluctuation due to thermal deformation of the satellite bus between the laser communication load and the star sensor must be constrained to within 0.16 mrad to meet the rapid acquisition needs of the laser communication satellite. This paper analyzes the satellite's in-orbit temperature field distribution, which is then used as the input boundary condition for the thermal deformation analysis. The optical axis angle fluctuation is reduced by the common reference optimization design. Then, adaptable isolation between the satellite bus structure and the reference support structure reduces the thermal deformation coupling. As a result, there will be less optical axis angle fluctuation caused by thermal deformation. The thermal deformation between the optimized laser communication load and the star sensor installation angle is decreased to 14.25\({}^{\circ}\) according to the entire satellite simulation analysis of the modified structure. The maximum angle variation induced by temperature change dropped from 117.74\({}^{\circ}\) to 10.72\({}^{\circ}\) through the ground temperature deviation and prism calibration tests. The on-orbit alignment test confirms that the required capture time of 30 s is met. The aforementioned work minimizes the uncertain region of laser communication load, lessens the in-orbit acquisition time, and satisfies the demand for speedy acquisition. F 2023 13502 2023  
suited to the development direction of downsizing. The field of satellite-to-satellite communication, as well as satellite-to-earth communication, can both utilize laser communication technology [8], and there is new progress in the study of atmospheric turbulence [9]. According to earlier research, the reduction of the in-orbit capture time of the laser communication payload is primarily carried out through the design optimization of the payload itself [10; 11]. The design of a communication satellite is a systematic project. The factors affecting the acquisition time of a laser communication load include not only the factors related to the load itself but also the orbit prediction error of the satellite bus, the attitude measurement error of the satellite, and the dynamic deformation error of the satellite [12]. The orbital state of the satellite, the load's operating mode, and the thermal design state must all be examined in order to determine the thermal deformation magnitude of the satellite [13; 14]. When the thermal analysis model has been established, the relevant thermal deformation situation is next examined in order to determine whether the thermal deformation's influence magnitude can meet the requirements of the laser communication load acquisition time. The degree of thermal deformation between the star sensor and laser communication load implemented in a honeycomb sandwich structure is discovered to be significantly greater than what is necessary for index allocation in this work. To control the angle variation between the laser communication load and the star sensor optical axis, it is important to optimize the thermal deformation. The goal of the optimization design is to establish a stable thermal deformation connection between the star sensor and laser communication load. This common reference optimization design idea is often used in remote sensing satellites [15], but it is rarely used in communication satellites. Second, it uses flexible isolation with the satellite bus to lessen the impact of the entire satellite's temperature variation on the support's temperature swings as well as the impact of the entire satellite's thermal deformation on the ambiguous zone of laser communication alignment. The flexible isolator used in this paper is usually used to reduce the effect of micro-vibration in orbit [16]. Finally, satellite load isolation was used to reduce the thermal control challenge, precisely manage the temperature of the isolated physical reference support, and lessen the impact of the physical reference support's temperature fluctuation.