In view of the safe and reliable transmission, processing and storage of smart meters and the cloud platform of metering master station in power Internet of things, a smart meter billing management model based on cloud security and homomorphism password in Internet of things environment is proposed. Firstly, network security detection based on cloud security is helpful to strengthen the security protection of smart meters in Internet of things environment. Secondly, homomorphic asymmetric key encryption technology is uesd to encrypt and upload customer data to the cloud, and allow the cloud to obtain the total energy consumption of users in a given period of time without decryption operation, so as to strengthen the protection of user privacy and data confidentiality. After that, combining Amdahl’s law and user-defined acceleration measurement, a parallel accounting algorithm is formed, which can fully improve the processing capacity of multi-core processor in cloud servers. Experimental results show that compared with the existing methods, the proposed model can significantly reduce the time required for smart meter billing and enhance the security protection and information processing capacity of smart grid on the premise of ensuring user privacy and data security.