The　Natural　Element　Method　is　a　mesh-free　method　based　on　the　evaluation　of　Partial　Differential　Equations　by　the　Natural　Neighbor　Interpolation.　It　uses　the　Voronoi　chart　or　Delaunay　triangle　as　the　background　integration　mesh.　The　mean　value　theorem　is　defined　that　the　value　of　the　center　of　a　globe　(or　the　center　of　a　circle)　in　the　unknown　function　definition　domain　is　equal　to　the　average　or　weighted　average　in　spherical　surface　(or　circumference).　It　is　fully　necessary　for　balance　equation　met　by　the　unknown　function.　Using　the　mean　value　theorem　and　the　point　integration,　the　average　strain　value　in　evaluation　domain　is　translated　through　divergence　theorem　into　perimeter　integration　in　domain　circumferences.　It　improves　the　traditional　integration　format.　The　difference　between　Natural　Element　Method　and　other　mesh-free　methods　is　mainly　in　the　following　two　aspects:　one　is　using　geometrical　measure　to　get　the　natural　adjacency　shape　function;　the　other　is　using　the　dummy　point　integration　to　form　the　stiffness　matrix.　The　count　cases　show　that　this　integration　is　an　adapted　numerical　method　which　can　greatly　simplify　the　calculation　of　the　program　and　improve　the　efficiency　of　computation.