The production of sludge has been sharply increasing in China. Drying is a good treatment method for its resource utilization, however, the process to deal with sludge inevitably generates wall-sticking phenomenon thus corrodes drying devices and reduces drying efficiency. In this paper, by applying free-falling detection, sludge adhering quantity was derived to represent the wall-sticking characteristics with respect to the influence of moisture, temperature and cathodic heat wall. The results show that paper sludge adhering quantity first rises then reduces according to the increase of moisture and reaches the peak at about 65%. Temperature tends to increase due to the joint impact of overtemperature and microbial protein to decrease the sludge adhering quantity which finally gets to a steady state. However, Sludge adhering quantity can be curtailed to acceptable twenty percent of its origin value resulted from cathodic heat wall which creates a water film isolating sludge and wall.