In order to develop environmental and degradable medical protective materials with the functionality of waterproof and moisture permeability, Poly (butyleneadipate-co-terephthalate) (PBAT) microporous membrane/hemp spunlaced nonwoven composite material was prepared. Firstly, hemp and cotton fibers were mixed and then spunlaced to prepare nonwovens. The PBAT microporous membrane was prepared on hemp/cotton spunlaced nonwovens via nonsolvent induce phase separation method. Single factor experiments were used to preliminarily explore the average pore size of microporous membrane/spunlaced nonwoven composite material with different casting solution concentration, pre-evaporation time and membrane thickness. Next, the optimal process of composite membrane was optimized by response surface methodology. The mechanical properties, pore diameter, contact angle, hydrostatic pressure resistance and moisture permeability of the materials before and after coating were compared and analyzed. The results show that the optimum preparation conditions of PBAT microporous membrane are as follows. The concentration of casting solution is 14.34%, the pre-evaporation time is 44.63 s and the membrane thickness is 0.16 mm. The mechanical property and hydrostatic pressure resistance of the composite material with the optimal process are larger than those of spunlaced nonwovens, the pore diameter and moisture permeability are smaller than those of nonwovens. The contact angle is slightly smaller than that of nonwovens.