Biofilm is the predominant form of life for bacteria in environments. The highly structured, matrix-enclosed, and functionally coordinated community protects bacterial cells from inhospitable environment. Biofilm-mediated pollution control has become an attractive approach in environmental engineering. In this review, the mechanisms through which bacteria interact with material surfaces and develop into biofilms in various environments are summarized; focuses are on the roles of pioneer bacteria in biofilm development, the dynamic changes in bacterial community composition, and the resistance to stresses as well as pollutant degradation characteristics of biofilms in unfavorable environments.