The design of the air conditioning system of the three-axis air bearing test bed directly affects the accuracy of the control system and the air-conditioning consumption.In this paper the thrust allocation problem in the air conditioning control of the three-axis air bearing test bed is studied.Aiming at the redundant thrust allocation problem two methods are designed to optimize the thrust allocation of the three-axis air bearing test bed.The corresponding theoretical analysis and experimental research are carried out from the perspectives of expense and accuracy.The rationality and effectiveness of the proposed method are verified by mathematical simulation and experiment.The research results meet the requirements of finding a good cold air thrust allocation scheme quickly after the expected torque is given the steps of thrust allocation are simplified and the problem of waste of cold air caused by the redundant allocation of the thruster is effectively solved and the control accuracy of air conditioning is within the design range.The experimental results show that the accuracy of air-conditioning control can reach 0.4° and the task of attitude control with only four thrusters at a time is realized.