The staple fibers and nonwoven geotextile is one of the most important material in the 12.5-meter deepwater channel project in the Yangtze River at the downstream of Nanjing. To ensure the accuracy of the tensile test results, through theoretical analysis and experimental comparison, the paper studies the influential factors of tensile test in the aspects of humidity, temperature, the width of the specimen and the tensile rate, and puts forward the precautions during the tensile test of polyester staple fiber nonwoven geotextiles.