The work aims to study the design innovation under the perspective of discursive design, realize the coupling of speculative design and product innovation through the hub of discursive design and construct a discursive design thinking mode based on speculative thinking, so as to supplement the methodological basis for speculative design. The method of model construction and practical demonstration was adopted. Firstly, the dialogical nature of discursive design and the product attributes of discursive design that encouraged dialogue were studied to construct a link between the two. Secondly, a discursive design thinking mode based on speculative thinking was proposed by integrating future thinking and deterministic design thinking. Finally, the feasibility of the thinking mode was demonstrated through design practice. The discursive design thinking mode based on speculative thinking realized the transformation of the core conversational issues through the construction of mapping scenarios, and then through the functional scenarios, the users could realize the dialogue with the designers through perceptual scenarios. The study explores a new design thinking mode other than deterministic design and speculative design, which on the one hand effectively undermines the elitism of speculative design, penetrates the discursive issues to the users through experience, and enhances the effectiveness and breadth of the dissemination of the discursive issues. On the other hand, this thinking mode facilitates designers to look for alternatives to business-oriented design methods and promotes innovation in the relationship between designers and users.