This paper introduces an on-site smart operation maintenance system for substation equipment based on mobile network. It consists of an operation and maintenance system platform located on the data center side and smart operation and maintenance boxes with its related APPs located on the on-site side. As the kernel of the system, the smart operation and maintenance boxes are bridges between the data center and operation sites. On one hand, it is able to formally upload data to the data center in real-time. One the other hand, the operation and maintenance personnel are able to call for help from the resource on the data center anytime. Using the system proposed in the paper, both efficiency of the operation and maintenance and the normalization of the data can be improved.