The invention relates to an in-situ interfacial polymerization method of a fiber-based conductive polypyrrole/carbon nano tube composite electrode material. The method includes the following steps that: cellulose fiber fabric is immersed in an aqueous-phase solution containing an oxidizing agent, a surfactant and carbon nano tubes; an organic-phase solution containing monomers and a surfactant is added into the mixture of the cellulose fiber fabric and the aqueous-phase solution dropwise; and after the organic-phase solution is added into the mixture dropwise, the newly formed mixture is put into an ice-water mixing bath so as to be subjected to oscillation reaction. According to the in-situ interfacial polymerization method of the fiber-based conductive polypyrrole/carbon nano tube composite electrode material, the micro porosity of cellulose fibers is utilized; and the flexible composite electrode material which is jointly composed of fiber, conductive polypyrrole and carbon nano tubes is prepared in an in-situ polymerization mode. Compared with a traditional in-situ chemical polymerization method, and with the method of the invention adopted, reaction time can be shortened, and the structure of the electrode material is more uniform and regular, and resistivity of the electrode material is lower, and specific capacitance and cyclic stability of the electrode material is high. The method has a bright application prospect in the fields of portable electronic and energy products and intelligent textiles.