Pneumatic　artificial　muscles　(PAMs)　are　expected　to　play　an　important　role　in　endowing　the　advanced　robot　with　the　compliant　manipulation,　which　is　very　important　for　a　robot　to　coexist　and　cooperate　with　humans.　However,　the　strong　nonlinear　characteristics　of　PAMs　hinder　its　wide　application　in　robots,　and　therefore,　advanced　control　algorithms　are　urgently　needed　for　making　the　best　use　of　the　advantages　and　bypassing　the　disadvantages　of　PAMs.　In　this　article,　we　propose　a　full-order　sliding　mode　control　extended　state　observer　(fSMC-ESO)　algorithm　that　combines　the　ESO　and　the　fSMC　for　a　robotic　joint　actuated　by　a　pair　of　antagonistic　PAMs.　The　fSMC　is　employed　to　eliminate　the　chattering　and　to　guarantee　the　finite-time　convergence,　and　the　ESO　is　adopted　to　observe　both　the　total　disturbance　and　the　states　of　the　robot　system,　so　that　we　can　inhibit　the　disturbance　and　compensate　the　nonlinearity　efficiently.　Both　simulations　and　physical　experiments　are　conducted　to　validate　the　proposed　method.　We　suggest　that　the　proposed　method　can　be　applied　to　the　robotic　systems　actuated　by　PAMs　and　remarkably　improve　the　performance　of　the　robot　system.　©　The　Author(s)　2021.