Abstract: For coal gasification technology, a general flame control technology is needed to ensure the stable combustion in the gasification furnace. And in the combustion process, the flame will produce huge amounts of charged particles, so that the flame has electrical properties, and can be affected by the electric field. In this study, a laminar flame experimental system under direct current electric field was designed and developed. A direct current electric field was applied to a methane-oxygen non-premixed laminar flame. Then the electrode spacing of direct current (DC) electric field and the combustion equivalent ratio of the laminar flame would be changed. The high-speed camera was use to record the rule of flame pulsation affected by the DC electric field. The effect of direct current electric field on flame stability was explored, and the feasibility of using electric field to confine the laminar flame was verified. The results show that, when high voltage direct current is applied to the flame, the laminar diffusion flame pulsation will be influenced by the effect of ion wind. The amplitude of flame pulsation will gradually diminish until the flame is in a steady state, and the electric field intensity which can stabilize the flame is associated initial pulse amplitude. The higher the initial amplitude is, the greater the voltage will be demanded. At the same time, the change of electrode spacing will also affect the electric field intensity required for flame stability. When the electrode spacing changes greatly, for the flame with the same equivalent ratio, the larger the distance is, the higher the stable voltage will be required.