A　high　pressure　common　rail　injection　system　model　based　on　lumped　parameter　method　was　built　up　and　used　to　analyse　main　factors　influencing　rail　pressure　fluctuation　in　commonrail　system.　It　was　concluded　that　they　were　engine　speed,　injected　fuel　delivery　and　current　rail　pressure.　Then　the　feedforward　control　logic　was　designed　by　adopting　maps　with　the　three　factors　as　independent　variables.　Furthermore,　the　PID　feedback　control　strategy　was　improved　by　taking　the　pumped　delivery　as　revised　PID　feedback　variable.　Finally　the　control　strategy　for　the　highpressure　common　rail　system　was　completed　and　verified　experimentally.　The　results　show　that　by　adopting　the　improved　closedloop　control　method,　the　rail　pressure　fluctuation　in　steady　state　conditions　can　be　reduced　from　about　±3　MPa　to　about　±0.3　MPa　while　pump　speed　950　r/min,　max.　cyclic　injection　delivery　230　mg/cyc　and　set　rail　pressure　160　MPa;　the　transient　overshoot　is　reduced　about　5　MPa,　stabilization　time　is　shorten　about　0.05　s.