Abstract: Based on hazard theory,the definition,classification,overall identification and control measures are analyzed in this paper.Hazard of coal mine is defined on the basis of present research and they are polarization relation between hazards and hidden troubles.Hazard is divided into condition hazard and root hazard which can be further divided into generic root hazard and specific root hazard.Not only procedure of hazard overall identification in coal mine but also methods of hazard control are put forward.There exit five methods of hazard control which removes,weakening,labor protection and training.