By exploring the needs of cloud pet people, analyzing the relationship between user needs and functional requirements, the absolute weight of functional requirements is obtained. Based on the weight of functional requirements, a cloud pet app with good usability is designed to meet the needs of pet people. Kano-QFD combination model is used as the usability research method of cloud pet app. Through the investigation and collection of pet users' needs, this paper uses Kano model to analyze the user needs elements and their importance of cloud pet app; dissects the user needs to obtain the corresponding functional requirements, and imports them into the QFD model to evaluate the correlation between the needs and the functional matrix, and obtains the functional requirements with higher correlation with the needs; the functional requirements are taken as the design basis, and the content of the design is optimized in combination with the EPO usability model. The information architecture, interactive prototype and visual interface of cloud pet app are designed. The reliability of the model is verified by eye movement experiment and SUS usability survey. Through the construction of Kano-QFD usability design model, the user needs analysis, the transformation of user needs to functional requirements, and the layer by layer transformation of detailed design steps based on functional requirements, the usability design of cloud pet app is realized, and the solution to similar problems is also provided.