The principle of analogy source design and functional analogy is introduced,and inspired by the connection between analogy design principle and TRIZ tools,the source design of function analogy process model based on TRIZ is established. Firstly,the relationship between user requirements and each function is obtained using function structure model. The related product function is endowed with the weight value of user requirements,and the functional similarity matrix constructed is standardized by Matlab tools. So the quantitative correlation between the source design and design problems is represented in the matrix. Finally,the process model of conceptual design based on TRIZ and function analogy is established. Functional similarity of the UV fume purifying machine and functional analogy source design is analyzed. Moreover,the obtained functional principle solution is evaluated by effective value analysis to validate the correctness of the model.