The work aims to analyze the human-machine relationship in the space station toilet, and evaluate its ergonomics, to provide theoretical methods and technical support for the ergonomics evaluation and design optimization of space station toilet. DELMIA software was used as the analysis tool to import the human body size model of the space flight crew after the modeling of the toilet environment in the space station to construct a human-machine simulation virtual scene. The toileting process in the space station toilet was decomposed, the toileting posture and comfort angle range of the human model were adjusted and the reachable visual field in the space station toilet was determined to carry out the simulation analysis and evaluation on the comfort of toileting posture in the space station toilet. According to the simulation results, the virtual toileting posture of space flight crew met the ergonomic requirements at all stages in terms of accessibility, visibility and comfort. The space station toilet can provide a comfortable toileting environment for the space flight crew and its overall structure and layout are in line with the ergonomic design principles.