To solve the problems of traditional optimizing methods which would produces huge amounts of date and obtain subjective result, an optimizing model for equipment system based on entropy and TOPSIS method is proposed. Based on optimizing target system of equipment system scheme, the model is built, and an instance is used as an example to verify the effectiveness of the method. The analysis shows that the method could improve the scientific nature, objectivity and effectiveness of scheme optimization, and give reference for the equipment experts in equipment system scheme optimization demonstration.