Measurement-while-drilling method and device for assessing outburst risk of coal seam

Disclosed are a measurement-while-drilling method and device for assessing outburst risk of a coal seam applicable to prediction of outburst risk and evaluation of gas drainage performance. The device comprises a compartment (20), a pressure sensor (17), a temperature sensor (16), a flow sensor (3), an electromagnetic sensor (19), an acoustic sensor (18), a wave velocity measurement module, a monitoring and control module (12), a power supply compartment (11) and a communication interface (9). The device is installed between a drill bit (1) and a measurement-while-drilling inclinometer (24) or a first drill pipe (23). The invention performs measurement while drilling a coal seam to obtain in real time gas parameter, lithologic and coal seam information, thereby realizing an on-site assessment of the outburst risk of the coal seam while drilling. In the process of drilling a coal seam and during replacement of a drill bit, the invention can monitor and record, in real time, and at a spot under measurement, a gas pressure, a temperature, a flow velocity, a wave velocity in a coal seam, electromagnetic radiation, and an acoustic signal so as to analyze and calculate to obtain a gas pressure, a gas content, an amount of initially desorbed gas, a lithologic character of a medium, a wave velocity, stress of the coal seam and coal seam outburst risk. The invention can perform on-site measurement while drilling without sampling and can use multiple parameters to perform synchronous measurement to obtain a comprehensive evaluation.