Partial discharge (PD) detection is a valuable method for the estimation of GIS condition, and the PD mapping is benefit for GIS defects identification. To investigate the PD characteristic of the GIS model, this paper simulates different PD maps of various fault simulations, and the characteristics of PD map is acquired by the pulse amplitude, phase and the discharge density to identify the discharge type effectively by characteristic parameters. To simulate the discharges in GIS there are five PD models are constructed in GIS, and this study may provide theoretical and practical bases for the GIS equipment estimation. Experiments show that this method using the PD map characters are effective for equipment estimation.