Cloud computing security system based on local area network

A cloud computing security system of a local area network relates to communication and data security of a cleaning system cloud platform, and comprises subsystems taking governments, various markets, sports halls, metros and large and medium-sized factories as subjects of implementation of the local area network; each local area network subject forms an internet of things local area network with a PROFINET, a switch, a PLC, a sensor and various types of cleaning devices configured as subordinates thereof; and a head quarter respectively makes databases according to types of client subjects, records optical disks and delivers the optical disks to a subsidiary corporation for performing offline backup storage, and makes various data codes in details for use in cloud communication. Each local area network runs independently, and is responsible for recording detailed operation and maintenance data, and when communication is needed, by an independent host or a mobile phone, an administrator can realize code commun