As the main form of small size bars producing ,the miniature continuous rolling production line assumes a large number of production tasks, the heavy work load and the complex work link make the key equipments subject to damage extremely. The paper made related research about three factors of “Man-machine-environment” by used method of system engineering, base on the practical data, analyzed various kinds of reasons which caused the damage of the miniature continuous rolling production line, construct hierarchical model combine with AHP, analyzed and calculated each factors, obtains the weight value, then gave targeted suggestions base on the date result. The Research Results do great practical significant to protect the key equipments on the line, save the production cost, and ensure working safety.