The invention discloses a copy-prevented Soc starting method and a chip thereof; the method comprises the following steps: generating scrambling keys key 1 of different versions, writing the keys key 1 into a storage medium area of the chip; putting encrypted data and program into an external storage device; during the starting process of the chip, configuring a symmetric encryption module key source as a storage medium key channel; descrambling the keys key 1 into keys key 0, and reading the keys into the symmetric encryption module; reading a cryptograph from the external storage device and inputting the cryptograph into the symmetric encryption module, starting to decrypting the data by the symmetric encryption module after receiving a decryption instruction; if the decryption is finished, putting a decrypted plaintext main program into a program running area of the chip; when all cryptographs in the external storage device are finished with decryption, closing the storage medium key channel, jumping to running in the plaintext main program; if the decryption is failed, suspending the Soc. The copy-prevented Soc starting method and a chip thereof are higher in safety and data copy prevention property; the cost is lower without limitation to the size of the encrypted data; the real decrypting keys key 0 are invisible during the whole production process, thereby reducing the risk of leaking the keys.