The invention discloses a test system for simulating flexible satellite three-axis attitude coupling movement with a single-axis air bearing table. The single-axis air bearing table is adopted for simulating the attitude movement of one axis of the satellite. The system comprises an attitude track control unit, an inertia reference unit, a mathematic model resolving unit, a control execution mechanism, an angle measuring device and a force moment output device, wherein the inertia reference unit is connected with the attitude track control unit, the mathematic model resolving unit is connected with the attitude track control unit, the control execution mechanism is connected with the attitude track control unit and the inertia reference unit, the angle measuring device is connected with the attitude track control unit, and the force moment output device is connected with the attitude track control unit. According to the test system for simulating flexible satellite three-axis attitude coupling movement, function extension is carried out on the single-axis air bearing table, the physical property and a mathematic model are combined, and resolving is carried out through the mathematic model, so that three-axis coupling force moment, flexible attachment disturbance force moment and space environment disturbance force moment borne by the satellite in the single-axis attitude movement process are achieved through a force moment output device, the effectiveness for verifying the flexible satellite single-axis attitude movement with the single-axis air bearing table can be improved, and the satellite ontrack single-axis attitude movement can be reflected more really.