The invention discloses a self-cleaning 
membrane structure and a preparation method thereof, and belongs to the field of building membrane materials. The self-cleaning 
membrane structure comprises a high-strength 
polyester fabric core layer, a strengthening layer, a 
polyvinyl chloride (PVC) function layer and a self-cleaning layer, wherein the PVC function layer comprises a 
creep-resistant layer and an anti-aging layer; and the strengthening layer is prepared from the following raw materials in parts by weight: 100 parts of 
polyvinyl chloride paste resin, 5 to 15 parts of 
polystyrene resin, 140 to 160 parts of dioctyl-
phthalate (DOP), 2 to 8 parts of liquid rare-earth stabilizer, 2 to 6 parts of liquid 
isocyanate cross-linking agent, 6 to 15 parts of 
flame retardant, 1 to 5 parts of octylphenol 
polyoxyethylene ether, and 5 to 15 parts of OS-20 
diluent. The self-cleaning 
membrane structure has the effects of better 
creep resistance, a better 
mechanical property and longer service life.The preparation method of the self-cleaning membrane structure comprises the steps of preparing raw materials; preparing the membrane 
layers: sequentially forming the strengthening layer, the 
creep-resistant layer and the anti-aging layer, and then plastifying; 
embossing; carrying out surface treatment to form the self-cleaning layer; 
embossing; and cooling to obtain the product. The product hasthe effects of better 
tear resistance and tension resistance, and higher membrane material peeling strength.