The integration of distributed generation and energy supply systems based on distributed resources is an important part of the future smart grid construction， and energy saving and emission reduction is one of the key targets in smart grid operation. Therefore， it is of great significance to carry out benefit research and analysis of energy saving and emission reduction for the planning and operation of smart grid. Action channels of energy saving and emission reduction of distributed resources are summarized comprehensively. The multi-objective optimization model which takes into account economy， environmental protection and reliability， is proposed. The objective function consists of minimizing the investment planning cost， unmet load and capacity shortage， and maximizing the total energy production generated by renewable sources. Dimension unity is obtained by means of penalties on emissions， unmet load and capacity shortage. Subsequently， the linear weighted sum method is utilized to transform the original problem into a single objective optimization problem. The dualistic factor contrast method is selected for indexes weight calculation while the criticality class of environmental protection is escalated in order to reflect the importance of energy saving and emission reduction. HOMER， the micropower optimization model， is utilized to simulate and optimize an energy supply system， and sensitivities of the results to different levels of emissions penalties， natural gas prices， annual average wind speeds and heat recovery ratios are examined.