An air-conditioning apparatus comprising: an outdoor unit including a compressor, a heat-source-side heat exchanger, and an accumulator, the compressor including a suction chamber having an injection port that allows refrigerant to flow into the suction chamber, the compressor being configured to compress and discharge the refrigerant, the heat-source-side heat exchanger being configured to cause heat exchange for the refrigerant to be performed, the accumulator being provided at a suction portion of the compressor and configured to accumulate the refrigerant; at least one load-side expansion device configured to reduce a pressure of the refrigerant; and at least one load-side heat exchanger configured to cause heat exchange to be performed between a load and the refrigerant, the outdoor unit, the at least one load-side expansion device, and the at least one load-side heat exchanger being connected by pipes, whereby a refrigerant circuit is formed to circulate the refrigerant, the outdoor unit including: an injection pipe having one end connected between the heat-source-side heat exchanger and the load-side expansion device and an other end connected to the injection port, the injection pipe being configured to allow part of the refrigerant in the refrigerant circuit to flow toward the injection port; an outdoor-side expansion device located between the one end of the injection pipe and the heat-source-side heat exchanger, the outdoor-side expansion device being configured to reduce the pressure of the refrigerant to adjust a flow rate thereof; and an injection expansion device configured to adjust an amount of the refrigerant that flows in the injection pipe, the air-conditioning apparatus further comprising a controller configured to control an opening degree of the outdoor-side expansion device and an opening degree of the injection expansion device characterized in that, when determining a discharge temperature of the compressor that is reduced because of a return liquid from the accumulator is lower than or equal to a predetermined liquid-level adjustment threshold, the controller controls the opening degree of the outdoor-side expansion device such that the discharge temperature of the compressor becomes higher than the liquid-level adjustment threshold. an outdoor unit including a compressor, a heat-source-side heat exchanger, and an accumulator, the compressor including a suction chamber having an injection port that allows refrigerant to flow into the suction chamber, the compressor being configured to compress and discharge the refrigerant, the heat-source-side heat exchanger being configured to cause heat exchange for the refrigerant to be performed, the accumulator being provided at a suction portion of the compressor and configured to accumulate the refrigerant; at least one load-side expansion device configured to reduce a pressure of the refrigerant; and at least one load-side heat exchanger configured to cause heat exchange to be performed between a load and the refrigerant, the outdoor unit, the at least one load-side expansion device, and the at least one load-side heat exchanger being connected by pipes, whereby a refrigerant circuit is formed to circulate the refrigerant, the outdoor unit including: an injection pipe having one end connected between the heat-source-side heat exchanger and the load-side expansion device and an other end connected to the injection port, the injection pipe being configured to allow part of the refrigerant in the refrigerant circuit to flow toward the injection port; an outdoor-side expansion device located between the one end of the injection pipe and the heat-source-side heat exchanger, the outdoor-side expansion device being configured to reduce the pressure of the refrigerant to adjust a flow rate thereof; and an injection expansion device configured to adjust an amount of the refrigerant that flows in the injection pipe, an injection pipe having one end connected between the heat-source-side heat exchanger and the load-side expansion device and an other end connected to the injection port, the injection pipe being configured to allow part of the refrigerant in the refrigerant circuit to flow toward the injection port; an outdoor-side expansion device located between the one end of the injection pipe and the heat-source-side heat exchanger, the outdoor-side expansion device being configured to reduce the pressure of the refrigerant to adjust a flow rate thereof; and an injection expansion device configured to adjust an amount of the refrigerant that flows in the injection pipe, the air-conditioning apparatus further comprising a controller configured to control an opening degree of the outdoor-side expansion device and an opening degree of the injection expansion device