Under the premise of intelligent and humanized development of medical equipment, the problems of obsolete styles and low user satisfaction of cabin fumigation products have become increasingly prominent. The work aims to conduct iterative design on cabin fumigation product to improve user experience. Based on the scenario method, the operation process of the existing cabin fumigation machine was sorted out, and the typical scenarios of the doctor, the patient, and the patient's accompanying person were established. The interactive design method was used to deeply explore the interactive friction points, organize the user needs, and reconstruct the target scenarios with good interactive performance. The analysis method of human interface elements (HIEs) was used to reconstruct the cabin fumigation machine. The mapping relationship between functional parts and functional components was established. Combining the target scenarios, functional requirements of the cabin fumigation machine were obtained. The functional model was created based on the black box principle, and the design goals of each functional component of the cabin fumigation machine were proposed. A cabin fumigation machine program that meets the needs of users was obtained. It verifies the feasibility of iterative product design with the scenario method and provides design directions and ideas for improving the usability and user satisfaction of similar products.