The invention relates to a cotton fabric pre-treatment and dyeing integrated low-temperature treatment method which comprises the following steps of: performing pre-treatment on a cotton fabric by using a one-dosage one-bath low-temperature pre-treatment composite preparation according to a bath ratio of 1:(10-20), preserving the heat at the temperature of 80-85 DEG C for 60-75 minutes, within heat preservation, directly adding a dye, discharging liquid, soaping, washing and drying. The one-dosage one-bath low-temperature pre-treatment composite preparation is integrated with multiple functions including refining, bleaching, permeating and the like; only one pre-treatment dosage is needed; inconvenience in operation caused by multiple dosages during production is avoided, and troubles in time consumption, labor consumption and material consumption are avoided; the using amount of auxiliaries such as caustic soda is reduced; by a one-bath method, the pre-treatment and the dyeing are combined; the technical flow is simplified; the treatment time is greatly shortened; the production efficiency is greatly improved; the treatment temperature is reduced; multiple washing and drying steps are eliminated; energy and emission are reduced; and the production comprehensive cost is reduced.