The invention discloses a hazard-free treatment system and method for electronic waste. The system comprises a material preparation system, a pyrolysis system, a casting machine, an oxygen supply system and a flue gas purification system. The material preparation system comprises a disassembling device, a waste storage bank, a weighing device, a conveying device and a physical crusher, wherein waste printed circuit boards and waste liquid crystal display screens are stored in the waste storage bank. The pyrolysis system comprises an oxygen obliquely-blowing revolving furnace and a feeder. Thetreatment method comprises the steps of 1, collecting and storing the waste printed circuit boards, the waste liquid crystal display screens, scrap copper and scrap iron; 2, conducting material preparation, weighing, material compounding, mixing and crushing, and delivering the materials into the feeder; 3, conducting feeding; 4, conducting reductive smelting; 5, conducting slag dumping; 6, conducting blowing; 7, conducting drossing and ingot casting; and 8, discharging a product out of the furnace, and casting an alloy plate. The hazard-free treatment system and method have the beneficial effects that smelting, reduction and refining can be completed in the same furnace, an additional smelting furnace does not need to be added, and inertia slag capable of being piled up is generated; andthe hazard-free treatment system can be completely closed, and the environmental requirement is met.