Sun's first start at a major international event took place in January 2005 at the Junior World Championship in Belgrade , where she immediately won the silver medal with the relay. In addition, she reached the final over 1500 meters, in which she was fifth, overall she achieved eighth place in the all-round competition. A year later in Miercurea Ciuc she was only used with the season with which she could even win the title. In the 2006/07 season, the Chinese Association nominated them for the first time for the Short Track World Cup . There she only started two races during her home World Cup in Changchun over 1500 meters, but here she placed on a very good fourth and also a good seventh place. At the Winter Universiade 2007 in Turin , Sun won the gold medal with the relay and the silver medal over 3000 meters. She also achieved top 10 results on the other distances. In the 2007/08 season she was used neither in the World Cup nor in a major event, but returned at the first station of the 2008/09 World Cup with a third place, her first individual podium result, over 1500 meters and a relay victory.
Note: This article places the family name before the person's first name. This is the usual order in Chinese. Sun is the family name here, Linlin is the first name.