The interfacial charge effect is crucial for high‐sensitivity organic phototransistors (OPTs), but conventional layered and hybrid OPTs have a trade‐off in balancing the separation, transport, and recombination of photogenerated charges, consequently impacting the device performance. Herein, a novel hybrid‐layered phototransistor (HL‐OPT) is reported with significantly improved photodetection performance, which takes advantages of both the charge‐trapping effect (CTE) and efficient carrier transport. The HL‐OPT consisting of 2,7‐dioctyl1benzothieno3,2‐b1benzothiophene (C8‐BTBT) as conduction channel, C8‐BTBT:6,6‐phenyl‐C61‐butyric acid methyl ester (PC61BM) bulk heterojunction as photoactive layer, and sandwiched MoO3 interlayer as a charge‐transport interlayer exhibits outstanding photodetection characteristics such as a photosensitivity (Ilight/Idark) of 2.9 × 106, photoresponsivity (R) of 8.6 × 103 A W−1, detectivity (D*) of 3.4 × 1014 Jones, and external quantum efficiency of 3 × 106% under weak light illumination of 32 µW cm−2. The mechanism and strategy described here provide new insights into the design and optimization of high‐performance OPTs spanning the ultraviolet and near infrared (NIR) range as well as fundamental issues pertaining to the electronic and photonic properties of the devices. A novel hybrid‐layered organic phototransistor, (HL‐OPT) architecture consisting of an organic semiconductor channel layer for fast carrier transport, a photoactive organic bulk‐heterojunction layer, and an ultrathin inorganic interlayer sandwiched in between is proposed. By combining the virtues of the charge‐trapping effect and efficient carrier transport simultaneously, significant enhancement in the photodetection performance is achieved from the fabricated HL‐OPT.