The invention relates to the technical field of washing and cleaning supplies, and particularly discloses a bacteriostatic hand-washing soap piece and a preparation method thereof. The bacteriostatic hand-washing soap piece comprises a film-forming agent, an amino acid surfactant, an anionic surfactant, a nonionic surfactant, fatty acid, alkali, a bacteriostatic agent, an auxiliary agent, an additive and water. The preparation method comprises the following steps: 1) adding the water into a container, then adding the film-forming agent, stirring, heating, and keeping the temperature constant after the film-forming agent is completely dissolved; 2) adding the amino acid surfactant, the anionic surfactant and the nonionic surfactant while stirring, and stirring for dissolving; 3), adding the fatty acid, stirring and dissolving; 4) adding the alkali under the condition of stirring, stirring for dissolving, and keeping the temperature constant until the system completely reacts; and 5) adding the auxiliary agent, the additive and the bacteriostatic agent, stirring and dissolving, and tabletting at 100-110 DEG C to obtain the bacteriostatic hand-washing soap piece. The antibacterial hand washing soap piece has the advantages of being mild and strong in cleaning strength.