In order to solve the problems in the design and implementation of current security access zone, such as poor universality, low transmission efficiency and lack of security, a design of power universal security access zone based on dual isolation is proposed. The design mainly includes the encryption and authentication device, the forward and reverse isolation devices and the universal access device. Based on the analysis of the structure and principle of the current security access zone, its shortcomings are given. By using universal access device, the design of security access zone is simplified, the no sense access of the two communication ends is realized, and the dual isolation of the security access zone and the encryption and authentication based on the state secret algorithm are realized. The results of test and verification prove the feasibility of the design and the test results of key communication and security parameters are given. Compared with the current schemes, the design has been improved in terms of universality, performance and security, and has good practicability.