The invention relates to a grounding method of a power distribution room. 10/0.4kV power transformation and distribution rooms are classified, the targeted grounding methods are proposed according to different classifications, so that the following effects are achieved: (1) the current existing in a grounding pole is reduced, and a grounding network is prevented from being corroded; (2) excessive small cross section of galvanized flat steel adopted in grounding conductors around the power transformation and distribution rooms is prevented so that the current thermal stability requirement of a large-capacity transformer during a grounding fault occurring cannot be met; (3) loop current is prevented from being generated in a ground line and a neutral line loop in a normal condition; and (4) the cross sections of a grounding connection line of a transformer neutral point and a grounding connection line of a PE busbar are reduced, and the grounding economy is improved.