The invention relates to a portable internet terminal of an electrical power system based on an ARM single board computer, composed of the ARM single board computer and a 3G module, a camera module, a liquid crystal screen, a touch screen, an audio module and a GPS module which are connected to the ARM single board computer through board-to-board connectors. The terminal is integrated with multiple functions; the defect that many large and heavy devices are carried to finish the site work of the electrical power system is solved; the working timeliness, safety and accuracy of the site worker of the electrical power system are improved; simultaneously the conductor at an operation monitoring centre can immediately know the working state of the site worker and exchange with the worker; and the efficiency of the power grid work is clearly improved.