Abstract: This paper experimentally studies the mechanical properties of polyurethane coated fabric in the simulated space environment. It is shown that, in high and low temperatures, the mechanical properties of one-side coated polyurethane aramid fibric are degradated; its tensile strength changes little in the high- and low-temperature cycling, the damp heat, and the sequentially-acted combined environment. The tensile properties of the double-coated polyurethane nylon fabric are improved in the low temperature, and degradated in the high temperature and damp heat environment; the high- and low-temperature cycling, and the combined environment has no significant influence.