Perovskite quantum dots (PQDs) have attracted much attention in the field of photoelectrochemical (PEC) sensors owing to their superb optical properties and efficient charge transport, but the inherent poor stability severely hinders their PEC applications. Herein, hydrolysis‐resistant CsPbBr3/reduced graphene oxide nanoscrolls (CsPbBr3/rGO NSs) are obtained by solvent‐assisted self‐rolling process toward water‐stable PEC sensors. CsPbBr3 QDs embedded in rGO nanosheets can be prevented from water since the multilayer rGO shell layers, which maintains excellent optical properties. On account of strong interfacial interactions, rGO nanosheets are crimped spontaneously with CsPbBr3 QDs, which offer access to superb structural and long‐term storage stability. Moreover, appropriate band alignment and ultrafast interfacial carrier transfer enable CsPbBr3/rGO NSs to exhibit greatly enhanced anode photocurrent response for subsequent PEC sensing. As a demonstration, the molecular imprinted PEC sensors for two kinds of mycotoxins (aflatoxin B1 or ochratoxin A) presents an ultra‐high sensitivity and good anti‐interference ability. Significantly, this work provides an inspirable and convenient route for hydrolysis‐resistant PQDs‐based optoelectronic and photoelectrocatalytic applications in aqueous ambience. Water‐stable CsPbBr3/reduced graphene oxide nanoscrolls (CsPbBr3/rGO NSs) are successfully achieved via rGO self‐rolling and CsPbBr3 encapsulation, appropriate band alignment and ultrafast interfacial carrier transfer enable CsPbBr3/rGO NSs to exhibit greatly enhanced anode photocurrent response for subsequent photoelectrochemical sensing. This work provides an inspirable and convenient strategy for hydrolysis‐resistant perovskite‐based further applications in aqueous ambience.