Abstract: In view of the problem that the partial discharge location detection of switchgear cabinet is susceptible to the accuracy of the detection instrument and the external environment,an improved three-dimensional space location method is proposed,which constructs the least squares objective function of the three-dimensional space where the partial discharge source is located,determines the initial value of the partial discharge source by using the bisecting plane method and accurately locates the partial discharge detect by using the intelligent search algorithm.The partial discharge location detection process of switchgear cabinet using the improved three-dimensional space localization method is determined and verified through the actul measurement of a 10 kV switchgear cabinet.The results show that the method can accurately locate partial discharge defects in the switchgear cabinet,and it features the uniqueness of the detection results compared with the bisecting plane method.