Complementation between natural gas and solar energy based on chemical looping exhibit advantages in low carbon emissions,energy storage, and high energy efficiency. Currently, typical reduction temperature of methane - based chemical looping is 800 ℃ .The conversion rate of methane is comparatively low at a medium temperature of 450 ℃ , resulting in reduced efficiency in both thermochemical energy storage and distributed energy systems. A novel thermochemical energy storage method was proposed to address thelow methane conversion rate under medium temperature conditions. The method involves the consumption of hydrogen by an oxygen carrier, leading to a decrease in hydrogen partial pressure, thereby shifting the reaction of methane reforming forward and subsequently enhancing methane conversion rates. Mechanistic experimental results show that the new thermochemical energy storage method of methane reforming coupled with chemical looping achieves a higher conversion rate than that of the traditional methane-based chemical looping. Methane is completely converted through multiple cycles at 450 ℃ . A multi-energy complementary distributed energy system model was established based on the new thermochemical energy storage method. Natural gas - solar thermochemical energy storage method elevateslow-grade solar energy to high-grade chemical energy while simultaneously achieving low-energy decarbonization. The solid fuel generatedfrom the natural gas-medium-temperature solar energy thermochemical method produces high-temperature thermal energy during the oxidation step. The high-temperature thermal energy is harnessed to generate electricity through a turbine, and subsequently, an excess heatrecovery system enables absorption refrigeration and heating, thereby achieving efficient complementary utilization of solar energy and fossilfuels. The operational performance of the system under typical conditions was investigated, showing that the distributed energy systembased on the new method achieved a net solar electricity generation efficiency of 24.90% and a fuel saving rate of 43.24%, demonstratingsignificant advantages in energy savings and emission reduction.