The invention relates to a device with multiple I2C (Inter-Integrated Circuit) buses, a processor, a system main board and an industrial controlled computer. The device with multiple I2C buses comprises a programmable logic device. The programmable logic device comprises a plurality of I2C bus controllers and a processor interface module, wherein each I2C bus controller has a master work module and a slave work mode, and each I2C bus controller is matched with a register set. The I2C buses of the processor are expanded by the programmable logic device, so that the processor can have a plurality of I2C bus channels. Multiple different units can be hung on each I2C bus, and the units can be master units as well as slave units to meet the requirements of certain specific application occasions, particularly monitoring systems. In the programmable logic device, each I2C bus controller only uses four registers, and therefore, the control complexity is largely reduced, the system can run stably runs and achieve high execution efficiency.