The application relates to the field of generator set operation and maintenance, and provides a large shaft grounding device, which comprises a fixing tool, a grounding wire, a constant-
voltage loading mechanism and a grounding shoe. The grounding shoe comprises a conductive base layer and a low-contact-resistance layer which are sequentially stacked. The conductive base layer is connected with the grounding wire. The constant-
voltage loading mechanism is connected between the fixing tool and the conductive base layer. The side surface of the low-contact-resistance layer opposite to the conductive base layer is an arc surface and is used for abutting against the surface of the large shaft. Based on the above structure, the electrostatic charge of the large shaft can be preferentially led away through the path of the low-contact-resistance layer, the conductive base layer and the grounding wire, the grounding effect of the large shaft grounding device on the large shaft can be effectively improved, the charge leading effect of the large shaft grounding device can be effectively improved, the accumulation of electrostatic charge to form a suspended potential can be effectively and reliably hindered, the
shaft voltage can be reduced, the risk of the breakdown
discharge phenomenon can be reduced, and the risk of the electric
corrosion of the bearing caused by the current passing through the bearing can be reduced.