The invention relates to a CAN (Controller Area Network) bus magnetic levitation ball control system and a bus communication method. After a distance signal between a detected steel ball and an electromagnet is inputted by a non-contact measurement device composed of a light source and a photoelectric position sensor into a processing circuit, the non-contact measurement device is connected with an A/D (Analog/Digital) converter; after being converted by the A/D converter, the data is sent to a first CAN node; a second CAN node is used for outputting a voltage signal through the A/D converter; a control signal is outputted by a driving circuit to an electromagnet winding to control the electromagnetic force; the two nodes are communicated with one another through a CAN bus to form a PID (Piping and Instruments Diagram) closed-loop control system; the current in the electromagnet winding is controlled, so that the electromagnetic force generated by the electromagnet winding is balancedwith the gravity mg of the steel ball; and the CAN bus is communicated with an upper computer PC (Personal Computer) through a CAN interface card. The CAN bus magnetic levitation ball control system has the advantages of openness, high reliability, strong anti-jamming capability, highly-decentralized system structure, decentralized risk and the like and is easy to install and maintain. Meanwhile,the CAN bus magnetic levitation ball control system also can be used for various control algorithms as well as the research and the practice of CAN bus communication theory.