Grid segmentation is an effective technique to improve the performance of multi-infeed HVDC systems. To study the performance improvement of different kinds of grid segmentation techniques in real power grids, the planning scheme of Guangdong Power Grid in 2030 is taken as an example, traditional LCC-HVDC (line-commutated converter HVDC) segmentation method, VSC-HVDC (voltage source converter HVDC) segmentation method and dynamic segmentation method are applied to the single-corridor interconnection schemeand double-corridor interconnection scheme respectively. The power grid’s performances are calculated and compared from three aspects: multi-infeed effective short-circuit ratio, impact of AC faults on DC systems, and short-circuit current control. Results show that different grid segmentation techniques have different impacts on the real power grid’s performance: the VSC-HVDC segmentation method performs better in all three aspects; the dynamic segmentation method is effective in controlling short-circuit current to a certain extent; the traditional LCC-HVDC segmentation method is effective both in reducing the short-circuit curent and in limiting the maximum number of DC system having commutation failure in AC faults. As for the the planning scheme of Guangdong Power Grid, the VSC-HVDC segmentation method improves the grid performance better than other methods under the double-corridor interconnection scheme.