The polypropylene (PP) fiber is modified with grafting and coating. The modified PP/Cotton fiber composite nonwoven is prepared with cotton and PP fiber via wet nonwoven papermaking method. Properties of composite nonwoven including morphology, electrolyte uptake, mechanical strength, thermal stability, ionic conductivity and the influence to battery performance are characterized. As a result, The modified PP/Cotton fiber composite nonwoven shows a better performance such as electrolyte uptake (180%), tensile strength (1.6529 kN m(-1)), size unchanged at 170 degrees C, ionic conductivity (1.76 mS cm(-1)), discharge capacities (169.9 mAh.g(-1)) and cycling performance (92%). Hence, the modified PP/Cotton fiber composite nonwoven is a promising separator for high-performance lithium-ion battery.