Air conditioner and air supply control method used for air conditioner

The invention discloses an air conditioner and an air supply control method used for the air conditioner. The air conditioner comprises a compressor, a four-way valve, an indoor heat exchanger, an outdoor heat exchanger, a liquid accumulator, a first throttling element, a second throttling element and a third throttling element, wherein the compressor is provided with a suction end, a discharge end and an air supply end; a first end of the indoor heat exchanger is connected with a third interface of the four-way valve; a first end of the outdoor heat exchanger is connected with a fourth interface of the four-way valve; the liquid accumulator is connected with a second end of the outdoor heat exchanger by a first liquid pipe, is connected with a second end of the indoor heat exchanger by a second liquid pipe, and is connected with an air supply end of the compressor by an air pipe; the first throttling element is arranged on the first liquid pipe; the second throttling element is arranged on the second liquid pipe; the third throttling element is connected between a first node and the air supply end of the compressor. The problem that the normal operation of the air conditioner in a low temperature environment cannot be ensured by a single air supply loop in the prior art is solved, the operation effect of the air conditioner is thus ensured, and the stability and the reliability of the operation of a unit are improved.