Abstract: As an important part of the communication network of ubiquitous power internet of things， the key management of charging pile communication system is important to the successful implementation of information security protection measure. In order to ensure the communication security of the three-tier architecture of backstage service management center， electrical control cabinet and electric vehicle charging piles， and to consider the efficiency of electric vehicle charging pile communication， a lightweight key management scheme （CPKMS） is proposed； The detailed implementation process of key generation， key issuance， key update and key destruction is proposed； Key security， forward and backward security， anti-attack capability， operation load and key storage quantity of CPKMS are analyzed. The analyzing results show that CPKMS can resist replay attack， forgery attack and man-in-the-middle attack. It has high security and efficiency， and can meet the safety requirements of the key management of electric vehicle charging piles.

Key words: electric vehicles charging pile, key management, charging pile key management scheme （CPKMS）, information security