Crowd sit-to-stand (STS) loading are always featured with pulse-like action, high crowd density and high synchronization rate among individuals, which may cause severe vibration comfort or even safety issues of supporting structures. However, related work in structural dynamics remains limited. As an early attempt, this study focuses on the individual STS loading and tries to develop an efficient tool to evaluate the potential dynamic response of the supporting structure when subjected to an individual STS action. Firstly, a comprehensive test campaign involving twenty participants was conducted by simultaneously footfall force measurement and 3D motion tracking of the human body. Secondly, the mathematical model of the individual STS loading was developed. Then a response spectrum framework that can give quick estimation of structural dynamic response induced by individual STS loading was proposed. The design response spectrum was formulated based on the measured force data. The effect of seat height, with or without armrests and the types of vibration assessment index on response spectrum was further discussed. The effectiveness of the method was finally verified on four full-scale structures having fundamental frequency from 2 Hz to 10 Hz subjected to individual STS actions.