Aiming at the complex elements and operation mechanism in the process of collective intelligence design, the work aims to study the creativity generation and knowledge resource utilization in collective intelligence design, and propose a method of cross-domain knowledge incentive to assist creativity generation in collective intelligence design. Firstly, the designers involved in the process of collective intelligence design are divided into groups to support the process of design inspiration and consensus. Secondly, a cross-domain knowledge base is built as an important tool in the process of design inspiration. Finally, based on the design group division and cross-domain knowledge base, the process framework of knowledge incencive and consensus building in collective intelligence design is constructed. A cross-domain knowledge incentive process and framework for collective intelligence design process is formed, which can further support collective intelligence innovative design. This method is conducive to the sharing and reuse of multi-domain design knowledge in the design process and can improve the design effect, promote the further development, and enrich the application scenarios of collective intelligence design.