The invention relates to a manufacturing method for a fully-integrated core of a side frame. The method is characterized by comprising the following steps of: firstly, manufacturing an integrated core box which comprises a side frame and an outer hook inner cavity structure, a triangular hole inner cavity structure and a central pane inner cavity structure are integrated in the core box according to the requirements of a side frame casting process; secondly, completing mold matching, sand filling, sand jetting, hardening, mold opening and core jacking actions under the cooperated actions of a core shooter and the integrated core box to shoot an integrated core at one time; and lastly, manually processing the surface of the integrated core. Due to the adoption of a core manufacturing process disclosed by the invention, the surface of the manufactured integrated core is smooth, the phenomena of casting scrap rubber and joint flash caused by the use of a diverse combined sand core can be effectively avoided, the internal quality of a casting is increased, and the working strength is lowered.