The　stiffness　of　the　cable　dome　structure　is　provided　by　the　initial　prestressing　force.　The　prestressing　force　loss　has　an　serious　influence　on　the　safety　of　the　structure.　The　design　and　construction　of　the　cable-strut　joint　is　the　key　technique　to　ensure　the　smooth　sliding　of　loop　cable　and　the　efficient　transfer　of　prestressing　force　to　loop　cable.　To　build　the　National　Fitness　Center　in　Ejin　Horo　banner,　Inner　Mongolia,　a　new-type　cable-strut　joint　including　a　sliding　bearing　is　invented.　It　essentially　changes　the　mechanical　characteristics　of　the　joint　and　can　decrease　the　prestressing　force　loss.　This　paper　analyses　geometrical　constitution　of　cable-strut　joint　and　makes　research　to　the　method　for　calculating　the　prestressing　force　loss　of　the　loop　cable.　The　nonlinear　contact　friction　finite　element　analysis　of　the　loop　cable　and　cable-strut　joint　was　carried　out　with　ANSYS.　The　prestressing　force　loss　was　calculated　through　the　monitored　data　of　the　model　experiment.　The　computed　results　are　compared　with　the　actual　monitored　data,　and　the　causes　for　large　monitored　pretressing　force　loss　were　studied.　The　following　suggestions　are　provided　for　cable-strut　joint　of　cable　dome:　the　constructional　detail　of　the　cable-strut　joint　should　be　improved　to　diminish　the　prestressing　force　loss;　the　prestressing　force　loss　value　of　cable-strut　joint　is　preferable　to　be　3%~4%,　meanwhile　the　cable-strut　joint　should　be　made　precisely　and　the　construction　should　be　controlled　strictly.