In　this　study,　the　effect　of　grouting　defects　on　the　tensile　behaviour　of　half-grouted　sleeve　connections　under　subzero　temperatures　was　investigated.　26　groups　of　78　half-grouted　sleeve　rebar　connections　were　fabricated　with　different　grouting　defects　under　different　curing　temperature.　The　effect　of　grouting　defects　on　the　failure　modes,　load-bearing　capacity,　and　deformation　capacity　of　half-grouted　sleeve　connection　was　analyzed　by　unidirectional　tensile　test　and　numerical　modelling.　The　results　showed　that　the　specimens　failed　due　to　rebar　tension　fracture　and　rebar　pull-out　attributed　to　bond　failure.　The　degree　of　grouting　defects　significantly　impacted　the　specimen　bearing　capacity　and　deformation　capacity.　With　the　increase　in　the　length　of　the　grouting　defects,　the　bearing　capacity　and　deformation　capacity　decreased,　the　bonding　improved,　the　safety　factor　decreased,　and　the　ultimate　elongation　did　not　meet　the　specification　requirements.　Horizontal　defects　had　the　most　significant　impact　on　the　mechanical　properties　of　the　specimen.　The　bearing　capacity,　deformation　capacity　and　bonding　properties　were　reduced　with　the　increase　in　the　defect　chord　height,　while　the　ultimate　elongation　could　not　meet　the　specification　requirements.　The　increase　in　the　water-to-cement　ratio　led　to　reduced　compressive　properties　of　the　grout,　significantly　decreasing　the　bearing　capacity　of　specimens.　When　the　curing　temperature　was　-　15　degrees　C,　the　bearing　capacity　and　deformation　capacity　decreased　significantly.　Through　finite　element　analysis,　the　simulation　results　were　found　to　be　consistent　with　the　experimental　results,　and　the　yield　load　and　ultimate　load　errors　were　within　5　%.