Since 2012 three cross-linked polyethylene (XLPE) insulated HVDC cables with rated voltage level of ±160 kV, ±200 kV and ±320 kV have been tested or successfully commissioned in HVDC transmission projects. They are Nan’ao three-terminal VSC project for island wind farm connection to China Southern Power Grid, with a total length of 37 km submarine and land cable of rated ±160 kV, which has been put into operation in December 2013; Zhoushan five-terminal VSC project with 294 km ±200 kV DC submarine power cable and has been in operation since June 2014; and another VSC project at the voltage level of ±320 kV is under construction in Xiamen, with a cable in length of 21 km deployed in cable tunnel. On the completion of these three projects within three years of time, China has realized triple leap in its HVDC submarine and land cable development. This paper presents the technical achievement of XLPE insulated HVDC cable development in detailed material characterization, space charge behavior, degassing processing and testing considerations. Their application in the three projects are introduced as well to illustrate the insulation and coordination design by considering each individual transmission system.