The present disclosure discloses a method for improving production of L-lactic acid (L-LA) by Saccharomyces cerevisiae based on regulation and control of ethanol metabolic flux, and belongs to the technical field of microorganisms. According to the present disclosure, acid-resistant Saccharomyces cerevisiae TJG16 is used as a production strain, an ethanol dehydrogenase gene adhA derived from Bacillus subtilis is introduced to promote conversion of ethanol into acetaldehyde, and a lactate aldolase gene BAL derived from Brucella sp. is introduced to promote synthesis of lactic acid from the acetaldehyde. Moreover, an acetaldehyde dehydrogenase gene ALD6 is knocked out to prevent synthesis of acetic acid from the acetaldehyde, a transcriptional regulatory factor encoding gene GAL80 for regulating and controlling galactose is knocked out, and lactate dehydrogenase LDH is integrated, so that the L-LA is finally increased.