The invention relates to a processing device, in particular to an environment-friendly iron leftover material recycling device for buildings. The environment-friendly iron leftover material recycling device for buildings is high in recycling efficiency, good in effect and easy to operate. In order to the achieve the technical goals, the environment-friendly iron leftover material recycling device for buildings comprises a trolley, a left support, a flame rack, a cleaning tank, a first motor, a processing tank, a steel plate, an electric push rod, a pressing plate, a sliding rail, a spring, a supporting rod, a sliding block, a rack, a third motor, a sector gear, a chain, a heavy pressing block, a flame sprayer, an electric control valve, a right support, a first air cylinder, a second air cylinder, a third air cylinder and an annular electromagnet. The left support, the flame rack, the cleaning tank and the first motor are arranged on the bottom of the trolley sequentially from left to right. The environment-friendly iron leftover material recycling device for buildings achieves the effects of being high in recycling efficiency, good in recycling effect and easy to operate.