Extracellular polysaccharides serve as the major structural components of Pseudomonas biofilm matrix, which can enhance the tolerance of bacteria for environment, antimicrobials and host defense. Pseudomonas mainly produce three key extracellular polysaccharides implicated in biofilm formation: alginate, Psl and Pel, and their synthesis and transport depend on the corresponding alginate, Psl and Pel biosynthetic systems. Therefore, this review comprehensively summarizes the progress on structural biology of Pseudomonas biofilm formation-related three exopolysaccharide biosynthetic systems, and describes the known structures and functions of proteins in these three systems. On this basis, new insights are put forward for future research directions, which can lay a solid theoretical foundation for formation mechanism and control strategies of Pseudomonas biofilm.