Abstract:Pervasive computing is considered as one of internationally recognized mainstreams of future computing. Trust-based Dynamic fuzzy access control model TDFACM in pervasive computing was put forward according to its security problem. This model combined traditional access control model with the theory of interval-vlaued fuzzy computing. Authorized decision will be made in accordance to the trust evaluation to the subject and the way of authorized fuzzy interference will be given as well. This mode can well solve the security and practicability of access control model in pervasive computing.