Based on multidisciplinary integration theory, this paper analyzes the current situation of intelligent product design for the elderly, and studies the process optimization ideas in design on the basis of understanding the product needs of the elderly users. By expounding the theories of systematization, framing, collaboration and optimization algorithm in multidisciplinary integration method, the platform users and designers are analyzed to find out the problems existing in the process of product design, and then the optimization ideas and methods are deduced with the support of service design principles and multidisciplinary integration theory. It is proposed that the design of intelligent products for the elderly is based on the users' operating experience and specific needs, and the design process involves multi-disciplinary and multi-objective. With the application examples of "multi-objective realization", "multi-disciplinary integrated system model" and "new technology integration", this paper explains how to solve the problems of calculation complexity and selection complexity caused by complex user requirements in the product design process, optimizes the design framework, sums up the design information, and improves the rationality, efficiency and accuracy of the design process.