"Basic knowledge of safety" includes laws and regulations on coal mine safety production, occupational particularity of electrical fitter in coal mine, coal mine production technology and safety knowledge, prevention and emergency avoidance of major disasters and accidents in mines, and prevention and control of occupational diseases. "Basic knowledge of safety technology" includes the safety of mine power supply system and underground power supply, the protection of mine power supply network, mine cables and their connecting devices, the safe operation of mine electrical equipment and the safety production monitoring system. "Practical skills" include the safe operation of underground power supply and electrical equipment, the safe operation of mining and transportation machinery and equipment, self-rescue, mutual rescue and on-site first aid.