Direct Z-scheme organic/inorganic semiconductor hybrid is seldom reported for photocatalytic H-2 production from water splitting. Reported herein is a new type of organic/inorganic hybrid fabricated with modified conjugated polybenzothiadiazole (B-BT-1,4-E, noted as BE) flake and CdS nanorod. The internal Z-scheme electron transfer mechanism is evidenced by detecting the loading position of Pt through a in-situ photodeposition technique. It is found that the Z-scheme BE-CdS hybrid possesses broad visible/near-infrared (vis/NIR) light absorption region (400-700 nm) and rapid photogenerated e(-)/h(+) separation rate. Photocatalytic performances reveal that the H-2 production rate of optimal cocatalyst-free BE-CdS hybrid is 8.3 and 23.3 times higher than that of CdS and BE respectively, and a high apparent quantum yield (AQY) of 7.5% at 420 nm is obtained over the hybrid catalyst. This work opens new opportunities for exploiting highly efficient solar water splitting performances.