The structure of frog eggs in the nature has inspiration for the designing of working fluids for solar thermal collection. This work explore the application of bionic structure mimicking frog eggs (BSMFE) as working fluid for solar photo-thermal conversion. According to the comparative experiments with Cu, CuO and carbon black nanofluids, it is found that the sustainability of suspension and photo-thermal conversion performance of BSMFE are better than those of other nanofluids, and BSMFE can achieve a higher heating rate in a short time. The performance of BSMFE-2 prepared from collagen protein and carbon black nanoparticles is better than that of BSMFE-1 prepared from bone glue and carbon black nanoparticles. This work provides an efficient but economical approach for industrial solar thermal collection.