The invention provides an automatic recognition method for measuring fissures of bridge structures. The method comprises the steps of: S1, fixing a laser ranging sensor beside a camera of an intelligent mobile phone and connecting the laser ranging sensor with the intelligent mobile phone through a connection line; S2, enabling the intelligent mobile phone to shoot a picture of a fissure, and automatically storing a shooting distance L from the mobile phone and the fissure through the laser ranging sensor; S3, carrying out edge detection on the picture shot by the mobile phone, calibrating theedge of the fissure and recognizing the position of the fissure in the picture; and S4, calculating the practical width of the fissure according to a coordinate conversion formula of a pixel count ratio of the width of the fissure in the picture and a practical physical with of the fissure. Compared with the prior art, the automatic recognition device and method for measuring fissures of bridge structures have the beneficial effects of being high in detection precision, low in cost and high in speed, and combining the intelligent mobile phone shooting and the laser ranging sensor to realize fissure recognition which cannot be realized by manpower.