Bacteria usually colonize, reproduce, and grow aggressively on chronic wounds in the form of biofilm. Different from free bacteria, bacteria in biofilm exhibit unique mechanism in epigenetics and biological behavior, especially in resistance to antibiotics and host immunity. In this article, we introduce the composition and structural function of bacterial biofilm, expound the drug-resistance mechanism of bacterial biofilm, discuss the clinical characteristics of bacterial biofilm infection wound and the diagnosis method of biofilm, and analyze the treatment strategy for bacterial biofilm. It is suggested that clinicians should pay more attention to bacterial biofilm infection and advocate in-depth study of bacterial biofilm in order to improve the quality of managing chronic wounds.