Solar interfacial water evaporation is an environmentally friendly and potential approach to producing fresh water. Herein, a PAN/CNTs-foam (PCF) evaporator with high porosity, hierarchical pore structure, and excellent solar absorption was successfully prepared by the vacuum casting method. The PCF prepared with a CNTs content of 17 % and NaCl particle size of 150–300 μm possessed an evaporation rate of 2.04 kg m−2 h−1 for pure water under 1 sun illumination. The PCF-2 showed a maximum evaporation rate of 5.60 kg m−2 h−1 for real seawater in outdoor experiments, and the quality of the produced clean water was also demonstrated. The purification ability of PCF for organic dyes further confirmed the potential usage in wastewater treatment. Particularly, the PCF-2 exhibited efficient and stable desalination performance for hypersaline water even in 25 wt% simulated brine due to the hierarchical interconnected channels. Our work offers a robust method for the construction of a 3D foam evaporator with hierarchical interconnected channels for efficient and sustainable hypersaline water desalination. Display omitted •A 3D PCF evaporator with hierarchical pore structure and controllable pore size was successfully prepared by the vacuum casting method.•The prepared PCF-2 evaporator showed a high evaporation rate and evaporation efficiency.•The PCF-2 evaporator possesses excellent salt resistance and can be for the treatment of hypersaline water.