AbstractMethods based on flow measurement and pressure measurement were employed in this paper to determine pressure relief scope of gas drainage boreholes for coal and gas outburst prevention and control. In order to measure the extent of pressure relief, the principle to choose proper sites was set up based on general gas geology features. The data acquired from underground testing showed that the risk of coal and gas outbursts has been eliminated in the scope of pressure relief. The exclusive method developed in the research could be utilized as the guidance for the future optimization of parameters for hydraulic flushing borehole arrangement