In　order　to　study　the　movement　principle　about　the　conjugate　side　of　a　new　type　opposed　biconical　cone　screw　high-pressure　seawater　hydraulic　pump,　motion　analysis　of　the　opposed　biconical　cone　screw　high-pressure　seawater　hydraulic　pump　is　carried　out　by　the　establishment　of　surface　equation,the　surface　and　the　solid　model　about　the　cone　screw　and　bush　which　are　the　main　components　of　the　seawater　hydraulic　pump.　Analysis　show　that　the　curves　of　the　ection　central　point＇s　displacement,　velocity　and　acceleration　about　the　screw　in　each　axis　component　are　the　periodic　curves,　the　period　of　the　curves　in　two　axis　of　the　end　is　the　time　which　the　screw　runs　around,　the　period　of　the　curves　in　axial　direction　is　the　time　which　the　screw　runs　a　half　cycle,　the　trajectory　about　the　section　central　point　of　the　screw　is　＇lip　curve＇　;　the　curves　of　the　each　point　on　exterior　surface　about　the　screw　in　each　axis　component　are　sine　or　cosine　curves,　the　cycle　of　the　curves　in　two　axis　of　the　end　is　the　time　which　the　screw　runs　around,　the　cycle　of　the　curves　in　axial　direction　is　the　time　which　the　screw　runs　a　half　cycle,　the　trajectories　about　the　different　exterior　surface　point　of　the　screw　is　different　size　oval.　©　2010　IEEE.