The lost circulation and the sulfured hydrogen corrosion are two problems in drilling in a fractured abnormal low pressure acidic gas field. To deal with these problems, the drilling fluid system for the lost circulation while drilling-LCM is developed. The related laboratory experiments and field applications were carried out. The LCM system consists of the desulphurization agent, the inhibitor, the corrosion inhibitor and the plugging agent, and it is shown to be of stable performance, good suspension property and good compatibility. This system has been applied in three wells. The application in the field shows that it can inhibit the sulfide effectively without affecting the drilling speed in the process of drilling, and can successfully build a man-made sidewall to plug effectively for the lost circulation interval of 110m rapidly. It is shown that the LCM system can effectively inhibit the sulfide with good liner cementation and geologic logs. The system can also reduce the operation time and the drilling fluid amount, thus to reduce the operation cost and shorten the operation cycle, as well as ensure the operation quality.