If　lateral　stiffness　distribution　of　continuum　structure　is　unreasonable,　its　displacement　distribution　will　be　non-uniform　under　lateral　load.　The　non-uniform　displacement　distribution　will　weaken　the　safety　of　the　structure.　The　continuum　structure　is　equivalent　to　the　cantilever.　The　optimal　lateral　stiffness　distribution　of　the　structure　is　obtained　by　adjusting　the　section　size　distribution.　The　wind　load　and　earthquake　action　are　simplified　into　three　equivalent　static　loads:　uniform　load,　inverted　triangle　load　and　inertia　force　related　load.　The　shearing　displacement　and　bending　displacement　distributions　along　the　structural　height　are　derived.　The　optimization　objective　is　that　the　second　derivative　of　the　total　displacement　distribution　is　zero,　that　is,　the　displacement　distribution　is　uniform.　The　section　size　of　the　cantilever　is　optimized　and　the　optimal　scheme　is　obtained.　The　optimization　results　are　verified　by　numerical　analysis　and　finite　element　analysis.　The　results　show　that　the　uniform　displacement　criterion　can　be　realized　by　the　cantilever　with　section　size　distribution　of　power　function.　The　optimal　parameters　of　the　section　under　different　loads　are　different.　A　practical　design　example　is　presented　to　prove　the　applicability.