Theoretical calculation can accurately identify the composition of power line loss and clarify that energy saving and consumption reduction point, which is an important technical management tool for reducing energy conservation and strengthening line loss management. The factors affecting line loss are divided into two categories of static factor and dynamic factor. By establishing an abnormal model of power grid line loss anomaly, the catastrophe theory is adopted to analyze the energy-saving and consumption-reducing points of the power grid under various factors, so as to achieve the purpose of reducing energy conservation and strengthening line loss management. The simulation results show that the catastrophe theory can accurately identify the key nodes of the power line loss and has a good practical application effect.