Interior graphic design is the first step in the process of decorating a rough house delivered by a real estate developer, floor plan design that meets the individual needs of users is a typical implicit optimization problem. The communication between designer and users is difficult to accurately obtain user needs, and the cost is extremely high. Based on the theory of optimal rules, the human-computer interaction mode in the interactive genetic algorithm is used to replace the cumbersome fitness function design with subjective evaluation to solve the above challenges. Experiments show that the algorithm can effectively meet the personalized needs of customers in the process of floor plan design. The improved interactive genetic algorithm introduces the subjective evaluation of users into the traditional design process, so that users can really participate in the design work.