The utility model belongs to a laser leveling instrument for measuring duct piece postures. The laser leveling instrument consists of a leveling instrument, the section of the horizontal ruler is rectangular; slots are formed in the left side end and the right side end of the horizontal ruler; adjusting bolts are respectively screwed on the horizontal rulers corresponding to the front side surfaceand the rear side surface of the slot; the front ends of the adjusting bolts located in the inserting grooves are in shaft connection with the middles of the rear end faces of the corresponding fixing plates respectively, the laser instrument with the display screen is fixed between the two fixing plates in the inserting grooves, a balance long level bubble pipe is arranged in the middle of the upper end face of the horizontal ruler, a clamping groove is formed in the middle of the front end face of the horizontal ruler, and a prism-free lens is arranged in the clamping groove. The duct pieceposture measuring device can improve the duct piece posture measuring precision, and has the advantages of simple structure, small size, compactness, reasonability, convenience in carrying and use, precision, stability, time saving and labor saving in measurement.