Reasonable setting of the turbulence model parameters is one of the key factors in the simulation of gas flow field. Investigators hold different views on the choice of turbulence model and the settings of turbulence model parameters around current zero. In this paper

aiming at the problem of the sensitivity of the turbulence model parameter C1 eon the gas flow field around current zero

the differences of the gas flow field caused by the C1 eare calculated

based on the magneto-hydro dynamic theory and the arcing simulations under a 252 k V puffer type structure. The reasons of the larger different values are discussed by comparing the gas pressure and the gas temperature at the specified monitoring points. The results show that the influence to the gas pressure within the nozzle area caused by the changes of turbulence parameter C1 eis smaller

but that to the gas temperature is larger.The sensitivity of C1 eon the gas flow field around current zero is restricted by the distributions of the gas flow field

and the effect of turbulence to the gas flow field is enhanced with the existence of the shockwave. It is acceptable for the calculating differences caused by the parameter C1 efrom the view of engineering application.The analysis of the sensitivity of C1 eon the gas flow field could provide a reference for the setting of the turbulence model parameters.