A new kind of waste liquid treatment device in the form of a counter flow in packed tower was proposed, and experimental researches on the heat and mass transfer performance between metal cutting waste liquid with 94% moisture content and unsaturated air were carried out. The inlet and outlet state parameters of the waste liquid and air were obtained under different operating conditions. Based on the NTU_m-Le model, the experimental data were processed by using the Le-α_m separation method to obtain the mass transfer coefficient α_m and Le number, and the heat transfer coefficient was then calculated. Finally, the influences of operation parameters on the heat and mass transfer coefficients and Le number were analyzed. The study finds that the increase of air flow rate, waste liquid flow rate and waste liquid temperature will increase the heat and mass transfer coefficients. The air flow rate and the waste liquid flow rate have little influence on the Le number which varies merely within the range of 0.96 to 0.99. The Le number decreases obviously from 1.3 to 0.71 with the increase of the solution temperature.