In　this　paper,　we　investigate　a　structural　parameters　model　with　the　trigonometric　method　in　order　to　improve　the　measurement　precision　of　the　binocular　stereo　vision　measuring　system.　We　find　the　relationship　between　the　accuracy　of　the　optical　locating　and　structural　parameters　through　analyzing　the　baseline(X　direction),　the　angle　of　view　omega,　and　the　convergence　angle　a　which　is　formed　by　the　baseline　and　optical　axes.　Finally,　we　will　represent　some　simulation　results　under　different　structural　parameters　where　the　optimal　range　of　the　structural　parameters　can　be　obtained　with　a　small　error.　Also,　the　correctness　of　the　theoretical　analysis　is　verified　by　experimental　results.