This　article　studies　the　mechanism　of　gas　film　damping　on　the　aerostatic　guideway　system　at　a　microscale　with　the　modified　Reynolds　equation.　The　slide　film　damping　force　due　to　the　fluid　viscous　effect　is　calculated,　and　the　squeeze　damping　force　caused　by　the　gas　compression　and　escape　between　two　plates　is　analyzed.　The　damping　ratio　in　the　calculation　model　for　the　slide　film　damping　is　compared　with　the　calculated　results　from　the　experiment　and　the　finite　element　analysis　results.　Using　the　results　of　the　study,　the　optimal　supply　pressure　is　designed.　The　method　applied　in　this　article　provides　the　theoretical　basis　for　the　analysis　and　solution　of　the　dynamic　performance　of　an　aerostatic　guideway.