A method for preparing a PBAT laminated membrane composite material uses PBAT or a material with PBAT as the main component and other biodegradable plastic or superfine calcium carbonate in a mixture. The temperature of the mixture is increased by means of a lamination machine segment by segment, the material is heated slowly to a molten state, and the temperature of a rolling shaft is controlled by introducing cold water to the rolling shaft when the lamination machine conducts membrane lamination, so that the temperatures of rolling wheels and the laminated membrane are controlled.
