Implantable neural interfaces represent a pivotal technology in the realm of brain science research. The primary research focus is on tackling the issue of bio-adaptation failure, which arises from immune rejection. This rejection is mainly due to interfacial adaptation imbalances between the implanted device and brain tissue across various characteristics. In recent times, hydrogels have gained recognition as promising materials for neural interfaces, owing to their high water content, low modulus, and biocompatibility. Nevertheless, faced with substantial challenges in microfabrication and inadequate electrical performance, the critical hurdle for hydrogel-based implantable neural interfaces is to attain a synergistic molecular and structural design. Such a design should harmonize micro-nano fabrication capabilities, efficient charge conduction, and long-term in vivo stability.