The waste heat utilization evaporator is an evaporation device that utilizes liquid or vapor waste heat. The waste heat utilization evaporator can utilize the sensible heat of materials or obtain flash evaporation to utilize their latent heat; Steam waste heat can be directly utilized for its latent heat.According to the degree of waste heat utilization, the waste heat evaporator can use less or even no steam, greatly reducing the operating costs of the evaporator and the energy consumption of the factory.