Through the discharge experiment of coaxial cylinder structure under non-equilibrium state, and the linear fitting analysis of the experimental data, the relationship between various characteristic parameters in the process of normal temperature air discharge is explored. The results show that the variation of frequency is the main factor directly affecting the plasma jet when discharge threshold voltage is satisfied. Adjusting the frequency leads to the change of jet length. Attributed to the standing waves of the electric filed, there exists mutation point of the plasma jet length. Although the relation between jet temperature and frequency is affected by the standing waves even leading to some mutation point, however the jet temperature and the jet length exists good linear relation. Also, experimental result demonstrates a linear relation between jet temperature and discharge voltage when threshold is met. When the gas flow rate is within 1 L/min, the variation of flow rate has a great influence on the jet temperature; While the flow rate is between 1 L/min to 4 L/min, it has less impact on jet temperature.