Abstract: To meet the application requirement of DSP system data security protection, a new security application mechanism based on AES algorithm is proposed without changing the DSP function. This mechanism integrates AES decryption module separately, and realizes data transmission control through software, optimizes the AES algorithm and replaces the design of the key extension module with the decryption key pre-written into the OTP, reduces the complexity of the hardware design, and realizes the data security protection function with the optimal resources. In order to ensure the compatibility and consistency of the area, the layout density was increased from 55% to 70% by optimizing the layout, and the circuit was successfully designed at the first time. The user's application results showed that the safety performance, data processing speed and electrical characteristic parameters of the circuit all met the application requirements of the system under the working frequency of 100MHz.