This paper investigates the distributed event-triggered predefined time secondary control and economic dispatch of microgrid, where voltage/frequency restoration and economic dispatch can be achieved on the same time scale. A distributed cost optimiser is proposed to maintain the economic operation of microgrid by balancing the incremental costs of distributed generator. A predefined time voltage/frequency regulator is designed to recover the voltage/frequency deviation caused by the droop control. Furthermore, an event-triggered control mechanism has been implemented in the designed controller to conserve system resources, and it is demonstrated that no Zeno behaviour occurs using the event-triggered function. Finally, the efficacy of the proposed controller is confirmed through simulation.