A coordinated control strategy is proposed based on state transition for a microgrid containing continuous or intermittent DG, energy storage device and sensitive loads. According to the available operation states, a scheme of operation state transition is established through setting the current operation state and trigger event as inputs of MGCC and regarding the control modes of components as outputs. By considering the no deviation control for frequency and the capacity limitation of energy storage device under all operation states, control modes of components and trigger events of state transition under all defined states are designed respectively for a reliable power supply of sensitive load. The PSCAD/EMTDC simulation software is used for analysis of the three typical transition processes of operation states. The results show that the proposed coordinated control strategy is effective for a safe and reliable power supply to the sensitive loads and ensures a smoothing transition between operation states of microgrid as well as the no deviation control of system frequency.