Modified heavy mechanized bridge is a set of equipment mainly used for bridging small and medium rivers, dry gaps and marshland, with a length of 75m and a depth within 5.5m, to ensure all sorts of tanks, artilleries and vehicles, and personnel to get across. The trestles are controlled by hydraulic winch; the outriggers can be adjusted by automatic control technology, with double class hydraulic cylinders. The bridge is erected with shear style erection, and span stretching at mean time to keep safety and stability in erection. It can be erected in night, time required is 1.5 times as that required at daytimes, and lapped on a highway bridge at ends. This bridge possesses the features of good mobility, quick erection, high mechanization, few operation staff and low labor intensity, it can be erected either in single span or in several span continually.