The invention discloses an air conditioner and an energy efficiency calculating method thereof. The energy efficiency calculating method thereof comprises following steps: the current
station and the
power consumption of the air conditioner, the power of a compressor, the high-pressure side pressure of an exhaust opening, exhaust opening temperature t2, the low-pressure side pressure of an air returning opening, the air returning opening temperature t1, the temperature t4 of the first end of an outdoor
heat exchanger and the temperature t7 of the first end of an indoor
heat exchanger are obtained; when the current
station of the air conditioner is the
refrigeration station, according to t1, t2, the high-pressure side pressure, the low-pressure side pressure, t4 and t7, the
refrigerant enthalpy values and lubricating oil
enthalpy values of the air returning opening, the exhaust opening, the first end of the outdoor
heat exchanger and the first end of the indoor heat exchanger are correspondingly generated; according to the
refrigerant enthalpy values and the lubricating oil enthalpy values, mixture enthalpy values h1, h2, h4 and h7 are generated; according to the power, h1, h2, h4 and h7, the
refrigeration amount of the air conditioner is generated; according to
power consumption and the
refrigeration amount of the air conditioner, the energy efficiency of the air conditioner is generated, so that real-time accurate detection of energy efficiency of the air conditioner is achieved.