General surgery hernia is a common and frequentlyoccurring disease in the world.In the tension-free hernia repair surgery,polypropylene( PP) patch has been confirmed as the most popular surgical implants.In this study, domestic medical PP monofilament was selected as raw material whose diameter was 0.15 mm,and the patch was knitted in the warp knitting machine of 12 E gauge with one bar.Using the method of orthogonal experiment with three factors and three levels,the best heat-setting process of PP mesh was determined at the temperature of 130 ℃ with 10 min under tension-free conditions.The relationship between heat-setting tension and performance of the patch was discussed.Patches with different porosity were prepared,and then structural parameters including density,thickness,porosity,and mechanical properties including tensile breaking strength, bursting strength, tearing strength,flexural rigidity and suture pulling out strength were tested and compared.The experimental results show that: the smaller of the patch’s density, the higher of the porosity; other properties including density, thickness, bending stiffness, tensile breaking strength,bursting strength,tear strength,and suture pulling out strength reduce in varying degrees.This different degree of reduction is worth summarizing. General surgery hernia is a common and frequentlyoccurring disease in the world. The tension-free hernia repair surgery, polypropylene (PP) patch has been confirmed as the most popular surgical implants. In this study, domestic medical PP monofilament was selected as raw material diameter was 0.15 mm, and the patch was knitted in the warp knitting machine of 12 E gauge with one bar. Using the method of orthogonal experiment with three factors and three levels, the best heat-setting process of PP mesh was determined at the temperature of 130 ° C with 10 min under tension-setting tension and performance of the patch was discussed. Patches with different porosity were prepared, and then structural parameters including density, thickness, porosity, and mechanical properties including tensile breaking strength, bursting strength, tearing strength, flexural rigidity and suture pulling out strength were tested and compared. experimental results sh ow that: the smaller of the patch’s density, the higher of the porosity; the other properties include density, thickness, bending stiffness, tensile breaking strength, bursting strength, tear strength, and suture pulling out strength reduce in varying degrees. reduction is worth summarizing.