The present invention provides a method for refined attitude control based on output feedback for a flexible spacecraft. The control method comprises the following steps of: a) building a flexible spacecraft dynamical system Σ1, converting the flexible spacecraft dynamical system Σ1 into a flexible spacecraft dynamical system Σ2, and incorporating spacecraft rigid-flexible coupling dynamic disturbance into the flexible spacecraft dynamical system Σ2; b) constructing an external system Σ3, and describing the rigid-flexible coupling dynamic disturbance through the external system Σ3; c) configuring a disturbance observer for estimating the value of the rigid-flexible coupling dynamic disturbance; d) configuring a dynamic output feedback H∞ controller; e) compounding the disturbance observer in step c) with the dynamic output feedback H∞ controller in step d) to obtain a flexible spacecraft refined attitude control system Σ6; the flexible spacecraft refined attitude control system Σ6 compensating for the rigid-flexible coupling dynamic disturbance through the estimated value.