Cavitation　is　one　of　the　important　elements　influencing　the　performance　of　sea　water　hydraulic　axial　piston　pump.　To　understand　the　working　performance　of　sea　water　hydraulic　axial　piston　pump　under　cavitation　effects,　a　fully　dynamic　numerical　model　was　developed　in　this　article,　which　has　taken　into　account　the　fluid　compressibility　effect,　dynamic　processes　of　gaseous,　vaporous,　pseudo-cavitation　and　cavitation　damage,　and　the　simulation　was　conducted　through　a　three-dimensional　computational　fluid　dynamics　code　PumpLinx.　The　cavitation　characteristics　of　the　pump　were　presented　with　a　set　of　working　conditions,　as　well　as　the　cavitation　damage　power,　dynamic　gas　volume　fraction　and　vapor　volume　fraction　inside　the　intake,　piston　and　port　plate　chamber.　A　test　rig　was　developed　to　validate　the　computational　fluid　dynamics　simulations　for　the　case　of　sea　water　hydraulic　axial　piston　pump.　Comparisons　between　the　measured　and　simulated　instantaneous　discharge　pressure,　average　flow　as　well　as　the　vibration　characteristics　under　different　extents　of　cavitation　by　varying　the　inlet　pressure　and　rotational　speed　of　the　pump　were　presented.