The attitude tracking control problem for spacecraft with limited communication is investigated in this paper by employing event-triggered based sliding mode control theory. Considering model uncertainties and external disturbances, the attitude dynamics are developed on the special orthogonal group SO(3) directly, avoiding singularities and ambiguities associated with other attitude representations. Based on the developed model, a coordinate-free adaptive event-triggered sliding mode controller is proposed to ensure the closed-loop system to be uniformly ultimately bounded, in which an adaptive fuzzy logic system is utilized to compensate the disturbance. The control signal is only updated and transmitted at some discrete instants generated by the designed event-triggering strategy, such that the communication burden can be decreased significantly. Finally, the effectiveness of the designed control method is demonstrated by numerical examples.