The effect of DC electric field on methane/air premixed flame was studied under the room temperature (298 K) and initial pressure Pinitial of 0.1-0.5 MPa. The results are as follows. The flame is mainly stretched in the horizontal direction with the applied voltage under different initial pressures. The change of the flame deformation increases with the voltage amplitude. The flame instability increases with the initial pressure. Compared to without the applied voltage

the flame propagation speed is improved obviously with the applied voltage

and the enhancement in flame propagation speed increases with the voltage amplitude and initial pressure

so the effect of the electric fields on the flame increases with the initial pressure. When λ=1.4

U=-10 kV

and Pinitial=0.1-0.5 MPa

the average flame propagation speed increases by 35.67%-52.71%. The enhancement in the mass burning rate increases with the voltage amplitude and the initial pressure with the applied voltage. The initial burning period and the main combustion period are shortened with the applied voltage

and the decrease in them increase with the initial pressure

and the change of the initial burning period is more obvious.