With　the　development　of　networking　technology,　traditional　access　control　methods　can　no　longer　effectively　deal　with　the　security　issues　in　open　networking　environments.　As　an　important　factor　in　network　security,　trust　can　be　an　effective　approach　to　solve　the　access　control　problem.　In　this　paper,　we　propose　an　access　control　model　based　on　trust.　In　the　model,　we　introduce　a　trust　computation　method　based　on　fuzzy　comprehensive　evaluation.　We　also　propose　a　permission　mapping　method　based　on　uniform　distribution　function.　Simulation　results　show　that　the　model　is　better　suited　for　access　control　in　distributed　environments.