Considering the complex constraints like the performance of the actuators and the spatial pointing of the sensors, this paper studies the attitude maneuver trajectory planning problem for the space vehicles. The attitude maneuvering trajectory planning model was developed, and then mapped into the so?named flat output space via the differentially flat theory, eliminating the differential constraints and decreasing the design dimension. The pseudospectral method was utilized to parameterize the flat outputs, and the conformal map and barycentric rational interpolation techniques were introduced to improve the ill?conditioning of the differential matrix such that the trajectory planning accuracy could be enhanced. Numerical simulation eventually verifies that the attitude maneuver trajectory under various constraints could be planned efficiently via the proposed method, providing some reference for the engineering application.