As the key equipment in power system，whether the operation status of transformer is correct or stable will affect the reliability of power supply． The inrush current of transformer can not only affect the correct rate of differential protection of transformer，but also cause serious electrical pollution to other equipment of power system． The occurring causes and influence of inrush current are pointed out． The current measures for the suppression of inrush current are reviewed，such as series resistance method in primary side，shunt capacitance method in voltage side and phase selection method． The advantages and disadvantages of each method are analyzed from the economic and technical aspects，the practical application of these methods at home and abroad is introduced，and the developing trend and research direction of the future attenuation methods for inrush current are prospected．