The problem of high communication frequency in the multi-hexacopter unmanned aerial vehicle (UAV) swarm system was addressed. A sliding mode control method based on event-triggering was proposed, utilizing a dual-loop structure control model based on sliding mode control of hexacopter UAVs. The model was comprised of a position subsystem and an attitude subsystem, with the position subsystem serving as the outer loop control object and the attitude subsystem serving as the inner loop auxiliary control object. In the position subsystem, position control of the hexacopter UAV swarm was achieved using a sliding mode controller with event triggers, which introduces sliding mode surfaces and sliding mode variables. The stability of the system under this control strategy was proven by the Lyapunov stability theorem, and the absence of the Zeno phenomenon was also demonstrated. Simulation results illustrate that the proposed control scheme reduces the reliance on high-frequency sampling of multi-agent communication. The research provides a useful reference for the application of hexacopter UAVs in collaborative path following.