Abstract In this paper, a distributed discrete-time event-triggered algorithm is proposed to deal with the economic dispatch problem with equality constraint. The communication can be reduced and the energy of systems can be saved by adopting event-triggered communication mechanism. The Zeno behavior is naturally excluded based on discrete iteration scheme. Moreover, the proposed algorithm has been proved to be exponentially convergent with the aid of convex optimization and Lyapunov stability theory that the optimal value is obtained with discrete exponential convergence rate. Finally, the effectiveness of the proposed algorithm is verified via a numerical example.