Abstract: New-type falling film evaporator—umbrella-plate falling film evaporator was introduced.Structure of umbrella-plateevaporator was explained.Heat transfer performance of the evaporator was studied with water and potassium carbonate solution as medium.Formula of dimensionless heat transfer coefficient on evaporation side of umbrella-plate falling film evaporator was obtained.By experimental investigation to break of liquid film at small flux,critical condition of liquid film break was got.This evaporator has wide application prospect which can realize multi-effect evaporation and is convenient to the reuse of low-grade waste heat.