Disclosed are a method for searching a cross-regional power supply area based on a common information model (CIM) and a system thereof. In the method, a hash function is first created according to a size of a power grid in which a power source is located; identification numbers of all devices in the power grid are mapped to a discrete hash table according to the hash function, and a collision is solved by using separate chaining; and a hash topological graph of the power grid is formed by using the discrete hash table; and a power supply area of a designated device is searched by using the hash topological graph. According to the present invention, devices in a power supply area are located rapidly and accurately by creating a discrete hash table for all device resources, so that the amount of computation is greatly reduced, and the efficiency of searching the power supply area is significantly improved.