Small and micro enterprise is a more special group in small and medium-sized enterprises, whose financing constraints are more serious. It is worth researching such issues deeply as the current situation, the special forms of financing constraints in small and micro enterprises, the perspective of financial structure over the small and micro enterprises financing constraints, and how to optimize the financial structure and formulate relevant supporting measures, so as to relieve the small and micro enterprises financing constraints, and promote the development of small and micro enterprises.