Conductors bounded by cylinders are not uncommon in our life and engineering practice, and infinite long straight wire is the most typical example, so it is necessary to study how to deal with problems related. At present, research on image method of conductors with cylindrical surface has been accurately obtained. However, this paper proposes a different solution, depending more on the geometric features of surfaces of conductors. Different from the conventional solution using the relationship between electric field and electric potential to solve distribution of electric field, this paper adopts the method of vector superposition, separating the size and direction of the electric field. In addition, this paper expands the scenarios applicable to the cylindrical image method, and applies the above ideas to the problems of boundary value of several special-shaped cylindrical conductors, which broadens the scope of application of cylindrical image method.