In design field, metaphor is a common approach to understanding an unfamiliar thing through familiar, including product appearance, function, and the intrinsic meaning. This study applies the similarity and metaphor theory based on contrast model and salience imbalance model to analyze the value of similarity, imbalance, and the between-domain distance of relationship between product metaphors. And it proposed calculations of similarity and imbalance. Finally, we compare the metaphor between the four design cases of metaphorical product by questionnaire data. Results include (1) most subjects prefer to identify the source of given product at form level. If the appearance of the product difficult to interpret the source, it will not be able to further judge the metaphor. (2) The value of salience imbalance, similarity, and between-domain distance are applicable to metaphor design in the field of industrial design. (3)Using multiple regression analysis summarized an equation that can predict the metaphor. The results of design cases were similar to the results of subjects.