A magnetic material used in the magnetic SF-based composite aerogel is a ferroferric oxide nanocubic particle, which is a magnetic nanomaterial with both excellent magnetocaloric performance and excellent photothermal performance. The magnetic SF-based composite aerogel prepared by the present disclosure exhibits excellent responsiveness to both alternating current (AC) magnetic fields and sunlight. Under an action of an AC magnetic field, the magnetic SF-based composite aerogel exhibits excellent temperature rise performance, which can inhibit the generation of biofouling in pores and channels inside a three-dimensional (3D) porous evaporation material. The magnetic SF-based composite aerogel exhibits excellent water evaporation performance under a sunlight irradiation, with a water evaporation rate of 2.03 kg m−2·h−1.