The present invention discloses a decentralized computing network system and a computing processing node (CPN) for the system. The decentralized computing network system consists of a plurality of CPNs, and each CPN is a computer with information receiving, processing and transmitting functions; each CPN conducts data interaction with its topologically adjacent CPNs; each CPN has a spatial attribute embodied as an absolute spatial position where the CPN is located and/or a relative spatial position of the CPN in a topological network; the decentralized computing network system is built-in with an operating system, and at least a part of operating system is distributed in each CPN; the operating system provides an API interface to convert a management/control demand and/or a strategy into a standard computation sequence, and into an instruction sequence recognizable by the operating system; the computing sequence is jointly completed by the CPNs in the decentralized computing network system in a decentralized and self-organized manner. The system can be applicable to a building automation system, providing an open and flat control platform which is easy to program.