The invention discloses a 
latent heat recoverable multi-
phase change sludge drying method and a 
latent heat recoverable multi-
phase change sludge drying device, which are designed for solving the technical problems that the 
energy consumption is high, the 
latent heat of the 
sludge vapor cannot be recovered and reused, the dried 
tail gas pollutes the environment, the 
operating cost is high and the like in the conventional sludge 
drying technology. Due to the combination of a low-temperature vapor turntable dryer, a sludge waste vapor latent heat recover 
heat pump and a 
tail gas purification device, and the use of indirect 
phase change heat exchange for low-temperature vapor, the heat exchange is improved, and the loss of organic components of the sludge is low. The latent heat of the sludge drying 
tail gas is recovered by using the latent heat recover 
heat pump, and the recovered 
heat energy is reused for sludge drying. Therefore, the heat efficiency is improved, the 
operating cost is reduced, and the problems that the heat utilization ratio is low, the 
operating cost is high and the like in the sludge drying process are better solved. The dried products meet the requirement of baking light and energy-saving bricks and producing 
cement laminated products, and over 90 percent of heat value of the original sludge is maintained. Therefore, the 
resource utilization value of the sludge is maximized.