In order to reduce the hidden trouble of flameout in the combustion process of low calorific value gas such as blast furnace gas, converter gas and so on, an automatic ignition technology is designed. The automatic ignition act when calorific value is more than 400, and the successful rate of ignition is more than 96%, which can resist the level 6 strong wind. By using catalyst, the ignition point of blast furnace (converter) gas can be reduced to 400 °C-500 °C (normal 600 °C), and the combustion intensity is increased at the same time, the stronger flame can be realized under the condition of less gas consumption, and the ignition temperature is lower than that of direct combustion, with the remarkable characteristic of low energy consumption.