Optoelectronic‐neuromorphic transistors are vital for next‐generation nanoscale brain‐like computational systems. However, the hardware implementation of optoelectronic‐neuromorphic devices, which are based on conventional transistor architecture, faces serious challenges with respect to the synchronous processing of photoelectric information. This is because mono‐semiconductor material cannot absorb adequate light to ensure efficient light–matter interactions. In this work, a novel neuromorphic‐photoelectric device of vertical van der Waals heterojunction phototransistors based on a colloidal 0D‐CsPbBr3‐quantum‐dots/2D‐MoS2 heterojunction channel is proposed using a polymer ion gel electrolyte as the gate dielectric. A highly efficient photocarrier transport interface is established by introducing colloidal perovskite quantum dots with excellent light absorption capabilities on the 2D‐layered MoS2 semiconductor with strong carrier transport abilities. The device exhibits not only high photoresponsivity but also fundamental synaptic characteristics, such as excitatory postsynaptic current, paired‐pulse facilitation, dynamic temporal filter, and light‐tunable synaptic plasticity. More importantly, efficiency‐adjustable photoelectronic Pavlovian conditioning and photoelectronic hybrid neuronal coding behaviors can be successfully implemented using the optical and electrical synergy approach. The results suggest that the proposed device has potential for applications associated with next‐generation brain‐like photoelectronic human–computer interactions and cognitive systems. A novel neuromorphic photoelectric device of vertical van der Waals heterojunction phototransistor based on colloidal 0D‐CsPbBr3‐quantum‐dots/2D‐MoS2 heterojunction channel is proposed using a polymer ion‐gel electrolyte as the gate dielectric. Efficiency‐adjustable photoelectronic classical Pavlovian conditioning and photoelectronic‐hybrid neural coding behaviors can be successfully achieved by utilizing the spatiotemporal and photoelectronic 4D synergy approach.