To　deal　with　the　weak　signal　strength　in　the　measurement　of　capacitive　proximity　sensors,　the　effects　of　geometric　parameter　design　were　investigated,　and　the　sensor　measurement　performance　was　greatly　improved　by　the　geometric　parameter　optimization.　The　comprehensive　evaluation　standards　of　sensor　performance　were　presented,　including　penetration　depth,　signal　strength　and　noise　tolerance,　measurement　sensitivity　and　dynamic　range.　For　round　capacitive　proximity　sensors,　the　effects　of　the　surface　area　on　sensor　performance　were　analyzed.　Four　different　structures　including　rectangular,　round,　interdigital　and　spiral-shaped　sensors　were　designed.　In　the　same　conditions,　the　electric　field　distributions　of　the　sensors　with　four　structures　were　simulated　and　the　measured　fringe　capacitance　was　compared.　The　results　indicate　that　the　geometric　parameters　have　remarkable　influence　on　the　measured　signal　strength　and　measurement　sensitivity;　comparing　with　rectangular　and　round　sensors,　the　measurement　sensitivity　of　interdigital　and　spiral-shaped　sesnros　was　increased　by　66.8%　and　33.5%.