From　the　purpose　of　ensuring　the　security　and　reliability　of　the　trusted　connect　architecture　(TCA),　the　issues　related　to　quantifying　its　security　attributes　were　studied,　and　the　security　threats　in　its　bi-directional　user　identity　authentication　and　platform　authentication　were　analyzed.　The　trusted　network　connect　process　under　attack　behaviors　was　modeled　as　a　stochastic　Petri　net.　This　model　was　used　to　describe　attack　behaviors　and　bi-directional　authentication　process　in　TCA.　The　main　security　attributes　of　confidentiality　and　integrity　were　analyzed　and　quantified　by　computing　the　steady　state　probability　of　a　Markov　model　derived　from　the　stochastic　Petri　net.　Finally,　the　model　analysis　was　illustrated　in　a　numerical　example.　The　method　demonstrated　in　the　study　is　of　theoretical　and　practical　significance.