As　the　primary　force　standard　in　the　super　large　force　range,　force　transducer　build-up　system　played　an　important　role　to　calibrate　the　build-up　force　standard　with　a　capacity　over　20　MN.　To　enhance　the　accuracy　of　the　build-up　system,　the　influence　of　build-up　structure　on　the　output　of　the　build-up　system　was　investigated.　The　parasitic　components,　including　the　side　force　and　the　additional　moment,　in　three　different　build-up　structures　were　analysed,　and　compared　by　the　finite　element　simulation.　The　experiments　of　three　300　kN　build-up　systems　of　the　three　structures　and　a　60　MN　build-up　system　were　carried　out.　The　experiment　showed　that　the　side　force　and　the　additional　moment　applied　to　the　transducer　had　significant　influences　on　the　output　of　the　transducer.　The　larger　side　force　and　additional　moment,　the　larger　the　position　error　and　the　indication　error　of　the　BUS　were.　The　side　force　and　the　additional　moment　should　be　minimized　during　the　build-up　structure　design.　The　pendulum　used　in　the　build-up　system　could　significantly　reduce　the　additional　moment　generating　on　the　transducer,　especially　after　the　pendulums　were　fixed　on　the　balanced　platen.　The　special　build-up　structure　with　the　pendulum　fixed　on　a　balanced　platen　was　verified　as　a　proper　build-up　structure.　(C)　2019　Elsevier　Ltd.　All　rights　reserved.