Abstract: The present invention relates to a method of purifying lake water using nano and micro bubbles, and more specifically, relates to a method of purifying lake water using nano and micro bubble comprising the steps of: contacting a first microbial fermentation broth to the green algae-generating treatment water area or the malodor-generating treatment water area by spraying means so that the green algae components and the malodorous components are decomposed; treating with nano bubbles in which nano bubbles generated by a nano-micro bubble generator selectively generating nano bubbles and micro bubbles are introduced into the lower portion of the treatment water area; and treating with micro bubbles mixed with microorganisms in which micro bubbles mixed with a second microbial fermentation broth are introduced into the lower portion of the treatment water area from a mixer in which micro bubbles generated by the nano-micro bubble generator and the second microbial fermentation broth supplied from a microbial inj