The invention discloses a method for synthesizing a PbTio3/RGO composite material through photocatalysis, PbTio3 is used as a photocatalyst, and under the protection of nitrogen and ultraviolet light-visible light irradiation, graphene oxide (GO) is reduced into graphene (RGO) through photocatalysis to form the PbTio3/RGO nano composite material which is combined by a Ti-O-C bond to provide an electron rapid transfer channel. The invention also discloses a PbTio3/RGO/GCE modified electrode and application of the PbTio3/RGO/GCE modified electrode in a high-sensitivity electrochemical detectionmethod for pyrrole. The synthesis method disclosed by the invention is simple, raw materials are easy to obtain, the price is low, the method has relatively high practical value, and the obtained nanocomposite material is good in electrical conductivity, high in catalytic performance and good in stability, and can be used for preparing the PbTio3/RGO/GCE modified electrode for high-sensitivity electrochemical detection of pyrrole.