Abstract: During the process of measurement of ⁴⁰Ar/³⁹Ar dating, the high precision of ages is limited partial by the stability of mass spectrometer, mass discrimination and the precision of the measurement of small ion beam. This study mainly described the advantages of Argus Ⅵ multi-collector mass spectrometer in application of obtaining accurate high-precision ⁴⁰Ar/³⁹Ar dating data. Through comparison of the measurement results of small ion beam ³⁶Ar collected by Faraday cup with 10¹² Ω amplifier and compact discrete dynode (CDD) respectively, it was found that the precision could be improved up to one order of magnitude if the signal size was smaller than 5 000 cps by CDD. The efficiency of CDD fluctuates lacked regularity as a result of environmental change and self-consuming, whose relative standard error was as high as 5.3‰ during continuous measurement, indicating that CDD should be calibrated frequently to avoid the obvious error of data. The air standard was determined for 60 cycles during 2 months with the mass discrimination factor d_1amu of 1.009±0.002 (2σ), indicating that the instrument was very stable, and different sizes of sample had little effect on the mass fractionation bias correction. Finally, two typical samples were chosen for ⁴⁰Ar/³⁹Ar dating measurement, the results showed that the CDD could improve the precision of the dating data for the sample which included extremely low ³⁶Ar. Meanwhile, the slight change of efficiency of the CDD could greatly change the ⁴⁰Ar/³⁹Ar calculation age when the sample included a certain atmospheric ⁴⁰Ar but lack of radiogenic ⁴⁰Ar, proving the importance of routine calibration of the CDD for the accurate high-precision ⁴⁰Ar/³⁹Ar dating.