In the process of smart grid maintenance, electrocution accidents occur from time to time due to mistakenly opening the maintenance power box, and it is necessary to design an adaptive protection strategy for the maintenance power box to reduce the occurrence of electrocution accidents. Based on blockchain and face recognition technology, the article establishes an overhaul safety identification model for power boxes. The model constructs the maintenance authorization system by configuring the authority range of maintenance personnel. Face information is extracted through the camera, and the blockchain technology is used to remotely obtain the information of work ticket and operation ticket to check the opening time of the maintenance power box and the authority of the personnel, so as to avoid electrocution caused by misoperation of unrelated personnel. Take the 0.4kV maintenance power box as an example to test the model of this paper. The model recognition accuracy reaches more than 90% under a variety of [25°,70°] face rotation angles, and has a good detection rate for strangers’ faces. Compared to traditional code-sweeping security recognition, the blockchain-based security recognition method takes less time, guarantees high accuracy, and is able to defend against multiple attacks.