According to relevant authoritative data, in June 1990 1 1, Lan became the deputy head of the jinniu district Municipal Government and the deputy secretary of the Political and Legal Committee of the District Committee.
Six years later, he left the political and legal system and successively served as the deputy director of Chengdu Construction Management Committee, the party secretary and director of the Municipal Bureau of City Appearance and Environmental Sanitation, and the party secretary and director of the Municipal Bureau of City Appearance and Environmental Sanitation.