Abstract: The filling effect is affected by various factors such as the backfilling step, roof support strength, mechanical properties of the filling body, real-time monitoring of the roof-to-floor convergence and the difficulty in real-time evaluation of the filling effect after filling the gob. In this paper, in view of the dynamic real-time monitoring needs of the gob roof, a new type of roof dynamic meters for the gob filling face was developed, focusing on solving key technical problems such as instrument height, waterproofing and real-time online monitoring, and applying it to the ultra-thin coal seam super high water material filling working face. The results show that the real-time roof-to-floor convergence of the gob is obtained through continuous and real-time dynamic monitoring of the roof during the filling process. According to the monitoring results, the filling process parameters such as the mechanical properties of the filling body are optimized and effectively reduced. The amount of the roof-to-floor convergence was decreased, and the filling effect evaluation threshold was placed forward, which achieved a good application effect.