There is an increasing need for application of biofilm process in the upcycling of wastewater treatment plants all around the world in recent years, yet there are few literatures on summarizing wastewater biofilm during the life cycle. In particular, there is a vacancy on characterization at various stages of biofilm and its regulation. This review provided a whole look at biofilm formation and its development, accompanied by microbial physiology, ecology, and activity, where the initialization of biofilm formation and its characterization were stressed. The new progresses on biofilm physio-ecology analysis and methods on evaluating microbial activity were summarized, while it is worth mentioning that the concept of aging biofilm was also presented. Furthermore, regulations methods of biofilm were reviewed and future research trends on biofilm control were prospected, aiming at guiding biofilm control in biofilm-based wastewater treatment.