Abstract: Spacecraft operating in low Earth orbit and deep space environments are prone to electrostatic discharge （ESD） phenomena induced by the complex effects of the space plasma environment, which poses potential threats to the on-orbit safety of spacecraft. To achieve the spatial positioning of ESD sources, a cm-level positioning technology for spacecraft ESD sources based on spatial electromagnetic radiation is proposed. Firstly, ESD radiated electromagnetic pulse simulation is carried out using CST simulation software to verify the feasibility and accuracy of the TDOA method, and the basic principle of the TDOA-DBSCAN positioning algorithm is systematically elaborated. Secondly, the time difference extraction algorithm for spacecraft ESD radiated electromagnetic pulse signals is improved by the time-window energy accumulation analysis method, which increased the relative accuracy of time difference by about 15%, and a TDOA-based ESD positioning model and a stepwise grid search solution algorithm are constructed. Since it is impossible to conduct tests on the complete structure of spacecraft in a ground vacuum environment, this paper conducts a comparative analysis of electromagnetic pulse signals in atmospheric and vacuum environments is performed to verify the feasibility of experiments in the atmospheric environment. Finally, a comprehensive spacecraft ESD experimental platform is built to verify the effectiveness of the proposed positioning method. Experimental results show that under the condition of a sampling rate of approximately 1.25× 10⁹ s⁻¹ , the spacecraft ESD source positioning algorithm based on spatial electromagnetic radiation developed in this paper can accurately locate the position of ESD sources, with an average positioning error of 15 cm.