Some problems have existed in existing techniques for monitoring gas buring. Based on the idea of sof-t sensing, a sof-t monitoring method is proposed, by which the state of gas burning and gas flowing are the secondary variables and the leakage ratio of gas is the primary variable. The implementation approach of sof-t monitoring method for gas safety is discussed in detail. The results show that the state of gas burning can be got by measuring the flame of the gas cooker by using the 0~ 800e temperature thermocouple, and the state of gas flowing can be obtained through convective heat transfer between flowing fluid and sensor element. The leakage ratio can be computed with the maximum flow rate, the additional safety coefficient and the minimum time during which the state from gas burning to gas going out can be recognized.