In this work, we report a high-performance photodetector based on perovskite CH3NH3PbBr3 quantum dots (QDs) films with a configuration of Au/CH3NH3PbBr3 QDs-Al2O3-indium tin oxide/Au as a bioinspired photoelectric synapse. The uniform CH3NH3PbBr3 QDs thin film is fabricated by a electrodepositing QDs solution and exhibits favorable long-term stability at ambient. By inserting an Al2O3 film, the dark current of the QDs film photodetectors is significantly suppressed as a result of the blocking effect, accompanied by the enhanced ON/OFF ratio. Furthermore, the optimal photodetector is utilized as a photoelectric synapse. Through modulating the light pulse stimuli, some underlying synaptic functions, including paired-pulse facilitation, axon-multi-synapses network function, and the transformation from short-term plasticity to long-term plasticity, are flexibly emulated on a single photoelectric synapse. These remarkable results are promising for building hardware units with neuromorphic architecture to mimic the human brain functionalities.