Abstract: The wet dust collector with a negative-pressure dehydration structure can effectively prolong the service life of the dust collector in the fast driving working face of semi coal-rock roadway with high driving speed, large dust production and high-viscosity dust, and has been widely promoted and applied in the fast driving working face. In order to solve the problems of difficult drainage and unstable drainage effect caused by the negative pressure dehydration layout of the mine wet dust collector, an adaptive negative pressure drainage structure is designed with the KCS−450D wet dust collector as the research object. The calculation methods of the spring stiffness and opening width of the drainage structure are determined by mechanical analysis of its working process. Moreover, the internal flow field conditions under different working conditions are simulated by the numerical simulation method, and the flow conditions of the internal flow field of the dust collector when the air volume processed by the dust collector is 300 m³/min – 450 m³/min are obtained. The negative pressure at the drainage pipe of the adaptive drainage structure varies between −1 604.1 and −2 499.8 Pa with the change of the treated air volume. According to the theoretical calculation and numerical simulation results, the parameters of the adaptive drainage structure suitable for the KCS−450D wet dust collector are finally determined and verified by laboratory tests and field applications. The laboratory test results show that the dehydration efficiency in the first 5 minutes after the dust collector is turned on is significantly better than that of the natural dehydration structure, and when the front - end resistance of the dust collector changes between 200 Pa and 2 000 Pa, the dehydration efficiency of the dust collector can always be maintained above 98%. The field application results of this adaptive drainage structure in the second section of auxiliary haulage roadway driving working face in Daliuta Coal Mine show that, compared with the original drainage structure of the dust collector, the new adaptive negative - pressure drainage technology can effectively prevent water mist from appearing at the outlet of the wet dust collector when the machine is started and the boom of the roadheader moves, improve the dehydration efficiency of the dust collector, prevent the impeller of the dust collector from adhering to dust, and further prolong the service life of the dust collector.