To address the issues of low accuracy and excessive complexity in ground-based three-degree-of-freedom air-floating platform simulations for autonomous spacecraft cluster docking experiments， we designed a continuous small-thrust， high-precision full-physical simulation system. This system was based on an embedded architecture and employed cascaded PID rotor propulsion control. Initially， a dynamic model for the ground-based full-physical simulation system， incorporating disturbance correction， was established. This model was developed based on the relative on-orbit dynamics of spacecraft clusters and the analysis of disturbances present in the ground simulation environment. A decoupled rotor propulsion system was then designed， which was integrated with a motion capture system， a master control host computer， and a lower control platform. The simulation spacecraft unit was developed using the μCOS operating system， and a three-degree-of-freedom motion control system was implemented based on a cascaded PID algorithm. Subsequent dual-spacecraft autonomous docking air-floating experiments were conducted to validate the system. The experimental results demonstrated that the simulation data generated by the dynamic model of the full-physical simulation system closely matched the experimental data. Specifically， the measured attitude pointing control accuracy of the ground simulation spacecraft was found to be no less than 0.1°， while the position control accuracy was no less than 1 mm. These results indicate that the developed system meets the high-precision requirements necessary for semi-physical simulation of autonomous spacecraft cluster docking. Furthermore， the successful implementation of this system provides a reference framework for the development of large-scale satellite cluster simulation systems. The approach described in this paper offers a practical solution for overcoming the challenges associated with ground-based simulations of spacecraft docking， ensuring both accuracy and system simplicity， which are crucial for advancing the study and development of spacecraft cluster operations.