The invention discloses an industrial or household Internet of Things system based on power line communication. The system comprises a power line coupling device and a power line application terminal.each power line application terminal corresponds to one application device; the application equipment comprises but is not limited to one or more of a computer terminal, an energy module, a securitymodule, a lighting module and an electrical equipment module. each power line application terminal also comprises at least one safety control part; the security control part is at least provided witha storage part, an operation part and an execution part, the storage part stores security information of the application terminal, and the security information of the application terminal comprises but is not limited to a security permission level, a security priority level, security algorithm information and a security execution level, so that the reliability and the security of the system are improved.