During normal operating conditions, current will flow through all elements of the electrical power system within pre-designed values which are appropriate to these elements’ ratings. Any power system can be analyzed by calculating the system voltages and currents under normal and abnormal conditions. Faults could happen as a result of natural events or accidents where the phase will establish a connection with another phase, the ground or both in some cases. Faults can also be defined as the flow of a massive current through an improper path which could cause enormous equipment damage which will lead to interruption of power, personal injury, or death. In addition, the voltage level will alternate which can affect the equipment insulation in case of an increase or could cause a failure of equipment start-up if the voltage is below a minimum level. As a result, the electrical potential difference of the system neutral will increase. Hence, people and equipment will be exposed to the danger of electricity which is not accepted. In order to prevent such an event, power system fault analysis was introduced. In double-line-to-ground fault, two phases to ground will be involved and 10% of all transmission lines faults are under this type of faults. In this paper, double-line-to-ground fault on Thanatpin transmission line is analyzed with Matlab simulation.