The patented technology of this invention relates to the principle, process and equipment of capillary evaporation, that is, based on the capillary rising phenomenon in liquid phase, that is, the surface tension phenomenon, and the inherent capillary rising phenomenon and surface tension phenomenon of liquid. The patented capillary evaporator realizes the continuous condensation and discharge of solvent vapor through the continuous reboiler evaporation of solution and the liquid surface tension of multiple capillary evaporation tube bundles, thus realizing the concentration of solution and the capillary condensation and separation of solvent vapor. Evaporative reboiler is realized by external heat source such as coil or short tube evaporation or external circulation or rising or falling film or molecular evaporation. Capillary evaporation condensation can be natural direct condensation or indirect wind condensation or indirect water condensation and cooling. Capillary evaporator can be used for single-effect or double-effect or triple-effect or multi-effect combination. Patent capillary evaporator has good evaporation effect, high working efficiency, energy saving, low carbon and high efficiency in heat energy utilization.