Aggregation induced emission (AIE) active molecules have emerged as a kind of unique and important functional materials of wide scientific and technical interests, but the photoelectrochemistry (PEC) of AIE-active molecules is still little understood to date. Herein, we investigate the first-time use of AIE-active molecules for PEC hydrogen production. Au nanoparticles (AuNPs) were electrodeposited on an indium tin oxide (ITO) electrode and AIE-active 1,1,2,2-tetrakis(4-(9H-carbazol-9-yl)phenyl)ethene (TCPE) was then electropolymerized to obtain a PTCPE/AuNPs/ITO photoanode (PTCPE = poly(TCPE)). Under 100 mW cm−2 AM 1.5G simulated sunlight irradiation at a bias of 0 V vs RHE in 0.5 M aqueous Na2SO4 containing 0.1 M ascorbic acid (AA), the photocurrent density of this photoanode was 1.32 mA cm−2 (0.16 mA cm−2 if simply without AA), which is notably higher than those of PTCPE/ITO (0.43 mA cm−2) and AuNPs/ITO (0.62 μA cm−2) control photoanodes. The excellent PEC performance is explained by the broadened light absorption range of PTCPE versus the monomer, the quenching of PTCPE fluorescence via the efficient electron transfer from the lowest unoccupied molecular orbital of PTCPE to AuNPs, and the consumption of the photogenerated holes on the highest occupied molecular orbital of PTCPE by AA, because all these factors can improve the separation and transfer of photogenerated charges. This work may have provided a reference for exploring new applications of AIE-active molecules and developing new PEC and photocatalysis materials.