Lane keeping assist system (LKAS) is an advanced assistant driving system, which can effectively avoid unconscious lane departures caused by drivers due to distraction, fatigue driving, insensitive response to emergencies, etc., reduce traffic accidents, and effectively improve Driving safety. This paper is committed to the research of LKAS standard of commercial vehicles in China. According to the working principle of LKAS and the test and evaluation methods of LKAS at home and abroad, the LKAS test scheme of commercial vehicles was designed after repeated discussions and demonstrations in many meetings, including straight and curve test scenarios. The actual vehicle test of commercial vehicle LKAS were completed by CATARC Automotive Test Center (Tianjin) Co., Ltd. in CATARC Yancheng Automotive Proving Ground Co., Ltd. The performance of LKAS of freight cars and passenger cars under different loads was studied. Based on the test results, suggestions on the formulation of domestic LKAS standards are put forward. This paper not only improves the domestic LKAS test method and evaluation system, but also provides reference for the formulation of domestic LKAS national standards.