The invention belongs to the technical field of graphite product preparation, and more specifically relates to a small-size graphite mould pressed block, and a preparation method thereof. The small-size graphite mould pressed block comprises an aggregate and a binder at a mass ratio of 70:30-75:25; the aggregate is petroleum calcined coke or pitch coke; and the binder is mid-temperature pitch. Thepreparation method comprises following steps: material preparation; primary milling; mixing kneading; material airing; sheet rolling; secondary milling; compression molding; roasting; dipping; and graphitization; wherein the step of compression molding is cold compression molding. According to the preparation method, cold compression molding is adopted, so that a paste material can be subjected to mixing kneading, sheet rolling, and secondary milling early, and stored, raw material characteristics are not influenced, and waiting of batch mixing is not necessary. The small-size graphite mouldpressed block is excellent in deformation resistance, deformation of mould pressed products can be controlled, the deformation rate is smaller than 0.1%, and using requirements can be satisfied.