The invention relates to an anti-electromagnetic interference molding piece which comprises a body and a conducting film covered on the surface of the body and is characterized in that the body is prepared by carrying out injection molding on a thermoplastic high polymer material; the conducting film is a carbon nano tube conducting film; and the body is mutually combined with the carbon nano tube conducting film through Van der Waals force. The invention also relates to a preparation method of the anti-electromagnetic interference molding piece. Compared with the prior art, the anti-electromagnetic interference molding piece and the preparation method thereof provided by the invention can ensure that the conducting film layer of the anti-electromagnetic interference molding piece has favorable uniformity, and molding products can obtain the anti-electromagnetic inference effect through simple manufacture procedures.