Firstly, the network diagram of energy supply and demand system was drawn then a linear optimized model of integrated energy with economy, the target of which is the least cost of energy supply, was developed to optimized the best energy supply structure. Secondly, according to above results, an SD model was built up to predict and to study the developmental changes of the system from the long point of view. Finally, the two models combined was applied to a village with a population of 800 people in the North China Plain and results of computer simulation showed on the base year (1990), if energy transformed devices were invested properly, the cost of energy supply system will be lowest on the condition of meeting the energy demand, at the same time it can save energy, and the energy supply is sufficient. But, with the development of economy and the upgrading of people’s living level, the energy supply will become an important factor for rural economy development. Several alternative plans designed to simulate the system gave different influences of energy to economy.