L in Zhijun is the vice chairman of Double Medical Technology, a major Chinese manufacturer of orthopedic implants and medical devices. He co-founded the company in 2004 with his brother, Lin Zhixiong. Double Medical specializes in trauma, spine, and joint implants, as well as surgical instruments, serving hospitals across China and internationally.

Based in Xiamen, the company went public on the Shenzhen Stock Exchange in 2017. Lin Zhijun has played a key role in the company's management and strategic development alongside his brother. His wealth is derived from his significant equity stake in the listed healthcare firm, which has benefited from the growing demand for high-quality medical consumables in China's aging society.