The invention discloses a gas spray culture method for improving quality and yield of lettuce. The problems in the conventional gas spray culture technology that the quality and yield of lettuce cannot be taken into account are solved. The method comprises the following steps: 1)accelerating germination of seeds; 2) growing seedlings in a manual climatic box; 3) transplanting seedlings; 4) preparing before field planting; 5) planting; 6) periodically regulating the pH value and EC value of the nutrient solution in the gas spray culture box; 7) replacing a standard nutrient solution; 8) replacing a nutrient solution of a low concentration before harvesting, namely (1) replacing the nutrient solution of the low concentration when the lettuce grows within one week before harvesting, removingthe residual nutrient solution in the spray culture box in an experimental group, and cleaning the residual nutrient solution of the root system with clean water; (2) shifting 6L of nutrient solutionprepared by a 1/2 standard nutrient solution formula into the spray culture box in the experimental group; 9) performing continuous supplementary lighting on plants within 1-2 days before harvesting;and 10) plant harvesting, namely (1) harvesting after the lettuce and cherry radish are planted by 30 days; and (2) harvesting the lettuce and cherry radish from the upper part and lower part of a planting cover plate.