Coal fires represent a worldwide hazard, and water mist is used as an effective means in controlling the fires. In the present study a new self-suctioning water mist generator was developed that produces efficient atomization at a relatively low pressure without the need for compressed air and improving the applicability of water mist systems in coal fire areas. The effects of structural parameters of the generator and operational variable (water supply pressure) on atomization performance were investigated. Both laboratory experiments and field tests were conducted to assess the fire suppression efficiency and cooling effects of this generator. The results show that the generator can attain a high degree of atomization after the optimization on the structural parameters and operational variable. The water mist produced by this device was also demonstrated to effectively suppress coal combustion. Compared with traditional water injection techniques, this new approach created more temperature decrease during a same period of application time while consuming an equal amount of water. This work therefore provides a practicable technique for the effective control of underground coal fires. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.