A kind of PV-energy storage microgrid in the park which includes distributed power generation, energy storage device, load and other controllable equipment is designed to meet the needs of reliable power supply of important loads when faults occur on distribution network and economic operation under grid-connected mode. This paper carries out the capacity allocation and control architecture design of PV-energy storage microgrid system, and develops key modules such as the microgrid central controller and the energy management system. The mode switching method provided by the central controller of the microgrid in the park under grid-connected mode or grid-disconnected mode can be used when faults occur on distribution network to ensure the stable power supply of important loads in the park and minimize the impact of distribution network faults. The economic dispatch model provided by the park's energy management system, aiming at the minimum operation cost, is solved by the commercial software CPLEX, and the optimal operation results of each equipment under many scenarios are given. The designed system has been successfully applied in industrial park and proved the rationality by the measured data. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900400) “Key Technologies and Demonstrative Application for the Integration and Consumption of Clustered Distributed Renewable Energy Generation”.