Abstract: With the continuous expansion of the distribution network，complex grid structure，perceptible mounting of new
services such as remote video monitoring and two-way real-time interaction ，it is urgent to combine the actual operation
scenarios of the distribution Internet of Things（IoT），different services，different security needs with different dynamic
access characteristics in studying the dynamic security protection system of the distribution IoT. As an emerging technology
in information security protection，trusted computing and blockchain can provide a secured and credible operating
environment and management mechanism for power distribution IoT. Therefore，based on a hierarchical credibility immune
management and control strategy for the master station and the terminals of the distribution IoT with a "cloud-edge-user"
architecture，a distributed decision-making and collaborative autonomy model for the distribution IoT taking blockchain
technology is established，and a "manageable，controllable，precisely protected，visual，trusted and intelligent " security
protection model for the distribution IoT is made. The model can comprehensively improve the information security defense
level of distribution network.

Key words: blockchain, trusted computing, distribution Internet of Things, endogenous security, distributed decision
making, collaborative autonomy, "cloud-edge-user" architecture, security protection model