Objective To study the characteristics of the plasma jet, improve the quality of the jet, and provide support for engineering practice. Methods Using the response surface methodology, the particle velocity and temperature were used as indexes to reflect changes in the jet characteristics. Box-Behnken design (BBD) was used to analyze the influencing law of electric current, main gas flux and secondary gas proportion on the jet characteristics and the parameter interactions. Results The results indicated that the particle velocity had the greatest effect on argon flow rate,followed by electric current and secondary gas ratio. To achieve optimal heating effects of plasma jet, the gas and electrical parameters matching scheme under the nozzle were: main gas flux 80 L / min, current 450 A, secondary gas ratio 22. 5% , whereas the parameters for optimal acceleration effect were: main gas flux 140 L / min, current 400 A, secondary gas ratio 15% . The AT40 coating prepared under the corresponding parameters of the optimal jet acceleration effect was uniform and compact, with low porosity. Conclusion It is scientific and reliable to use response surface methodology to study the characteristics of the plasma jet, and it can provide effective guidance in coating preparation.