Motion simulators have increasingly been applied for research purposes due to their large motion capabilities and short response time. Key applications are including vehicle simulation, experiments on control behavior in virtual environments and studies into human self-motion perception. To maintain a good dynamic capability, the known motion simulator usually has a custom-designed cabin with optimized stiffness and weight to encapsulate the various moving components. However, the particular shell structure is very inflexible for exchanging its functions. To improve the functionality of the motion simulator for conducting multi-purpose research, a modular cabin structure with flexibility and time efficiency when exchanging setups is demanded. This research project is based on a practical design task of a multi-purpose research cabin for a hexapod motion simulator installed at the Max Planck Institute for Biological Cybernetics. It is aiming to develop a simple cabin structure with more modularity while maintaining acceptable dynamic capabilities. In this project, a detachable structure concept is proposed based on a systemic assembly break down of the cabin entity into a base frame, an outer structure frame assembly and filling-in panels. Each part is designed as a self-supported substructure that could provide sufficient stiffness individually. Connections between each substructure is proved to be stiff and will not reduce its stiffness during motion also at higher frequencies. The designed cabin can access the limited motion lab entrance as disassembled parts and can be reassembled again inside the room. It has optimized setup positioning and high modularity for exchanging its functions. With bolted connection, the side panels can be removed fast for exchanging setups and repositioned back easily. The design of a modular cabin structure has contributed to the desired multi-functional research motion simulators.