Six years later, Lü joined the Ministry of Machine Industry of China, as the Department Head of automobile Industry; and then was promoted to the Deputy Minister of Machine Industry. During the eight years in office, he had made tremendous contribution to China's Automobile Industry, and personally involved in a number of projects. He also invited Wan Gang, a Chinese expert on automobiles who at that time was working with German Audi Corporation, to return to China.
Since 1998, Lü was assigned to be the Deputy Minister in Ministry of Education, and then Foreign Trade and Economic Co-operation.
In March 2003, the former Ministry of Foreign Trade and Economic Co-operation (MOFTEC) went through a reorganization and was renamed as Ministry of Commerce. Lü was promoted to be the first Minister of Commerce. However, after less than one year in the office, Lü resigned on 29 February 2004 due to liver cancer and died three months later.