Abstract: In order to realize fast and real time decision for Web resource access control,an improved algorithm called AC-BMH-QS is proposed.This algorithm based on existing algorithms contains two progresses for pretreatment and matching.The reversed finite automaton is built in pretreatment progress with values of two displacement functions calculated.The finite automaton is matched with object string in matching progress,in which the larger value of two functions is the distance that automaton moves.Factors that influence performance are analyzed according to examination results.And the results show that this algorithm could predigest calculation and advance efficiency.