Based on coal mine fully mechanized working face of low voltage power supply system was difficult to meet the demand of power supply situation, Xingtai mine of Jizhong Energy Corporation, shearer 's power supply and the startup mode were improved, single loop power supply replaced double circuit power supply and made the shearer two loop delay start, improved the demand factor of shearer and starting current. Results showed that the double circuit delay launch of shearer power supply mode was single loop power supply for shearer and it was more suitable for xingtai mine actual production needs.