The invention provides a bow net state detection method. The method comprises the steps of acquiring an original image of an intersection area of a contact line and a pantograph; obtaining straight line features of the contact line through a straight line extraction algorithm; further obtaining a linear feature according to the linear feature; fitting a virtual two-dimensional model of the contactline in a dynamic weight linear clustering manner; carrying out three-dimensional matching on the virtual two-dimensional model to obtain parallax information, then obtaining three-dimensional information, creating a virtual three-dimensional model of a contact line, and obtaining the state of the pantograph net according to the virtual three-dimensional model of the contact line and the virtualthree-dimensional model of the pantograph. Through the method provided by the invention, the contact line in the rigid contact network can be accurately identified, and the device for identifying anddetecting is simple in structure, low in cost and good in effect. In addition, the bow net state can be continuously and automatically detected through the bow net state detection method provided by the invention, the labor intensity of workers can be effectively reduced, and the working efficiency is improved.