The system commissioning of Xiamen flexible HVDC transmission project is analyzed and summarized. The design and preparation of the system commissioning program and the implementation of field system commissioning are introduced. The problems found during the system commissioning are analyzed and rectification methods are given. Three innovation test methods in the process of commissioning are elaborated including test method for true bipolar passive inverter, short time de-block technology, system commissioning isolation technique which effectively guarantee the safety of equipment and improve the quality of system commissioning. The summarized commissioning experience and methods are good guidance and reference for the construction of following projects.