Abstract: To address the sensitivity challenges inherent in gravitational wave detection instruments, this study unequivocally established the paramount indicators for both interferometer measurement noise and the proof mass residual acceleration noise within “Taiji Project” spacecraft. System noise was meticulously decomposed, revealing 26 distinct categories of interferometer measurement noise and 21 categories of residual acceleration noise. A comprehensive modelling approach was undertaken with specific focus on electromagnetic force noise. Through the design of a dedicated simulation system and subsequent calculations, the engineering viability of the spacecraft design proposal was verified. The simulation indicated that total electromagnetic force noise, calculated using parameters attainable with present-day engineering technology or parameters projected from the key technological roadmap, could satisfactorily meet the demanding requirements of gravitational wave detection missions. The findings of this research not only offer a robust framework for simulation and calculation of future noise variables, but also lay the groundwork for refining the indicator system of spacecraft design.