The structure and biocompatibility of anode materials significantly affect the performance of microbial fuel cells (MFCs). A biocompatible polyaniline-sodium alginate (PANI-SA) composite was prepared in situ oxidation polymerization on the 3D porous nitrogen-doped carbon nanotube/sponge (NCNT/S) to construct a high-performance microbial fuel cell in this investigation. The SEM showed that PANI-SA composite anode had a three-dimensional macroporous structure, and nitrogen-doped nanotubes were wound around the sponge skeleton, which had a large specific surface area, provided more places for the attachment and growth of microorganisms. A dual-chamber MFC equipped with a PANI-SA/NCNT/S bioanode to achieve a power density of 4380 mW m(-3), which was much greater than the other MFCs. During the charge-discharge time of 60-90 min, the PANI-SA/NCNT/S bioanode had the highest total charge value of 26,617.86 C m(-2), which was 3.23 times higher than that of NCNT/S (8231.87 C m(-2)). High-throughput sequencing results showed that the PANI-SA/NCNT/S bioanode exhibited high community diversity and selective enrichment of electrogenic bacteria. The excellent performance of the MFC equipped with PANI-SA/NCNT/S anode was attributed to the composite materials, which could be attributed to the large-pore network structure, better biocompatibility, large capacitance and high specific surface area. [GRAPHICS] .