In　research　on　dynamic　measurement　of　behavior　trustworthiness　of　complex　concurrent　computer　systems,　how　to　solve　state　space　explosion　caused　by　fine　grained　dynamic　measurement　is　a　difficult　point　up　to　the　present.　Based　on　concurrency　theory,　we　researched　behavior　trustworthiness　of　complex　concurrent　computer　system　and　reduced　the　state　space　on　the　premise　of　ensuring　reliability　of　measurement.　We　described　behavior　system　through　the　model　of　Labeled　Transition　System　and　researched　behavior　relationship　through　the　model　of　event　structure,　then　we　reconstructed　all　paths　in　the　transition　system　according　to　the　behavior　relationship　and　combined　like　paths　in　order　to　reduce　the　set　of　transition　relations　and　narrow　the　state　space.　The　situation　of　state　space　explosion　can　be　relaxed　through　the　methods　mentioned　above　and　meanwhile,　the　behavior　expectation　of　trusted　dynamic　measurement　can　be　obtained　according　to　the　reduced　state　space,　which　enhances　the　feasibility　of　the　method　of　fine　grained　trusted　dynamic　measurement　applied　in　a　complex　system.