The utility model provides a drift wall caving section measuring device, belongs to mine tunnel measuring instrument technical field for measure drift wall caving section. Its technical scheme is: T style of calligraphy tripod level is placed, and adjustable landing leg is installed in the lower part of T style of calligraphy tripod, and the protractor is installed at T style of calligraphy tripod upper surface, and the protractor plane is perpendicular with T style of calligraphy tripod plane, and electro -optical distance meter connects the front end at the protractor pointer. The utility model discloses an adjustment electro -optical distance measurment(EDM) makes it to read the distance and the angle of measuring point from the position of appearance on the protractor, and is a plurality of through measuring on the same cross -section, and then measures a plurality of cross -sections in tunnel to this obtains the disconnected profile of surface of wall caving, and it must wall caving side's volume to calculate again. The utility model discloses simple structure, convenient to use can carry out the rapid survey to the tunnel, and data accuracy and accuracy are high, can guarantee measuring result's accuracy, compare with traditional measuring tool, and convenient and fast, measuring result are more accurate.