In　the　software　testing　process,　in　order　to　complete　the　verification　of　software　credibility　and　improve　the　efficiency　of　software　testing,　this　paper　proposes　a　software　testing　method　that　combines　software　credibility　with　software　test　case　automatic　generation　technology.　First,　a　credible　behavior　declaration　for　the　software　under　test　is　generated　as　a　standard　for　verifying　software　credibility　and　algorithm　initial　values.　Then,　in　the　selection　of　test　case　generation　algorithm,　this　paper　proposes　an　improved　particle　swarm　optimization　algorithm　(DACSPSO).　The　experimental　results　show　that　the　automatic　generation　model　of　credible　test　cases　based　on　behavior　declaration　can　verify　the　credibility　of　the　software,　and　at　the　same　time　improve　the　efficiency　of　software　testing.