Refrigerant　injection　techniques　are　usually　proposed　to　improve　the　performance　and　reliability　of　compressors　when　a　single-screw　compressor　applied　to　an　air-source　heat　pump　works　at　low　temperatures　in　winter.　In　this　study,　an　experimental　study　was　conducted　to　present　the　performance　comparison　of　the　single-screw　compressor　in　the　air-source　heat　pump　under　liquid,　vapor,　and　liquid-vapor　refrigerant　injection　at　evaporation　temperatures　between　-19　and　-8　degrees　C.　The　results　indicate　that,　when　the　evaporation　temperature　decreases　from　-8　to　-19　degrees　C,　the　heating　capacity　under　liquid-vapor　and　vapor　injection　increases　by　16.7%　and　12.7%,　respectively,　compared　with　that　under　liquid　injection　and　that　the　COPh　increment　under　liquid-vapor　injection　and　vapor　injection　is,　respectively,　from　11.23%　to　39.21%　and　from　17.18%　to　30.82%　compared　with　that　under　liquid　injection.　Therefore,　the　liquid-vapor　injection　method　is　conducive　to　the　operation　of　the　air-source　heat　pump　at　a　lower　ambient　temperature.　The　experimental　results　can　provide　the　basis　for　the　future　design　of　single-screw　compressors　applied　to　air-source　heat　pumps.　(c)　2024　Author(s).　All　article　content,　except　where　otherwise　noted,　is　licensed　under　a　Creative　Commons　Attribution　(CC　BY)　license(https://creativecommons.org/licenses/by/4.0/).