For the refrigerant mass measurement of heat exchanger, a new measurement method, QOMM, is put forward. The deviation range of QOMM is 0.42–0.64%. Compared with LNM, QOMM can make the refrigerant flow back to refrigerant system, which can avoid the refrigerant waste and accelerate the measurement process. QOMM has 19% and 57% measurement time shorter than LNM for pure refrigerant (azeotrope refrigerant) and zeotrope refrigerant, respectively