Analysis　was　conducted　on　the　optimization　of　heat　exchanger　networks　of　propylene　oxide　production　system　using　chlorohydrin　method　based　on　pinch　technology,　and　the　optimization　methods　of　whole　system　and　subsystems　were　used　to　compare　with　each　other　for　better　optimization　method.　Aspen　software　was　used　to　verify　the　data　of　each　stream　taken　from　the　whole　process　system　and　to　calculate　and　analyze.　The　results　showed　that　the　current　network　temperature　difference　of　pinch　point　was　30　K,　the　temperature　of　pinch　point　of　the　whole　system　was　329.5　K　and　the　temperature　of　pinch　point　of　subsystems　was　327,　329.5　and　317.2　K,　respectively.　The　optimization　method　of　whole　system　heat　exchange　network　could　achieve　energy　saving　target　for　595.3　kW　which　took　up　17.47%　and　5.23%　of　the　hot　and　cold　utilities　of　original　system.　The　optimization　method　of　subsystem　heat　exchange　network　could　save　610.6　kW　which　took　up　17.91%　and　5.36%　of　the　hot　and　cold　utilities　of　original　system.　The　optimization　method　of　subsystem　heat　exchange　network　was　better　for　the　optimization　of　heat　exchanger　network　of　propylene　oxide　production　system　using　chlorohydrin　method.　©　2015,　Science　Press.　All　right　reserved.