Smart meter is an important intelligent terminal in the measurement automation as the billing between the power company and the user，the traditional key management methods of intelligent terminals have some problems，such as low efficiency，large traffic and vulnerability to network attacks. Therefore，in this paper a key management method of intelligent terminals based on attribute base encryption and threshold secret sharing is proposed. Firstly，group authentication is used to authenticate the identity of smart meters，which reduces the number of one-to-one authentication communications. Then，（t，n）-threshold secret sharing technology is used in identity authentication，and attribute base encryption technology is used in key generation process to hide access structure and avoid leakage of smart meter information. Finally，there are many kinds of security threats in the network. Large data technology is used to mine the types of network attacks in order to quickly identify malicious attackers. The proposed method is simulated to verify its effectiveness. The simulation results show that compared with other technologies，the proposed method significantly reduces the storage burden of the system，improves the communication efficiency，and takes less time to identify malicious participants，thus ensures the security of key management.