Disclosed are a method and system for generating a nanobubble-containing liquid. First, a liquid is introduced into a gas-containing pressure vessel by means of an atomization nozzle, the liquid forms liquid drops in the pressure vessel, and the gas diffuses into the liquid drops under a pressure higher than the atmospheric pressure; then, the gas-containing liquid in the pressure vessel is delivered to a narrow space, and the size of at least one dimension of the space is less than 20 mm; and finally, the gas-containing liquid is ejected from the narrow space into an open environment, with the pressure of same being lower than the pressure of the narrow space.