Water hyacinth is one of the most dangerous foreign species,harming public interest in Fujian Based on a complete investigation of different mechanical control measures and their successful applications in controlling the infestation of water hyacinth in China,this paper focuses on evaluating the emergency functions of mechanical control over water hyacinth and its good economic benefits.In order to get rid of hidden danger of water hyacinth,the paper raises a general idea and countermeasures to treat water hyacinth.The paper states that a daily clearing of water hyacinth mechanism and an emergency mechanism should be established to keep clean of water-head and to utilize comprehensively the water hyacinth in an attempt to control the water hyacinth at a lower ecological level.