The invention relates to a simple universal preparation method of a monodisperse phenolic resin nanorod in-situ-embedded MOF (metal-organic framework) composite. The simple universal preparation method comprises the steps of dispersing monodisperse phenolic resin nanorods evenly in a solution, adding a metal salt, stirring, carrying out ultrasonic treatment, adding a solution having a certain concentration and containing organic ligands, allowing to react, centrifuging, washing, and drying to obtain the monodisperse phenolic resin nanorod in-situ-embedded MOF composite. Compared with the priorart, the simple universal preparation method has the advantages that the synthetic process is simple, and the cost is low; in-situ doping of N helps effectively improve conductivity and electrochemical properties of the composite; MOF particle size is adjustable, the MOF can be embedded or inserted into the monodisperse resin nanorods stably, and the whole structure is stable; one-dimensional nanorods enable the inside of the large-particle-size MOF to be effectively utilized, so that an electron transport path is shortened and electron diffusion resistance is deceased.