The invention relates to an automatic assembling machine for a lamp bracket. The automatic assembling machine comprises a rack, a workbench and a multi-station rotary disc, an upper chassis station, an upper connecting sleeve station, an upper top disc station, an edge overturning station and a discharging station are sequentially and evenly arranged above the multi-station rotary disc, a riveting pressing station is further arranged on the outer side of the discharging station, a chassis containing mechanism and a chassis feeding mechanism are arranged on the outer side of the upper chassis station, a connecting sleeve feeding mechanism is arranged above the upper connecting sleeve station, a connecting sleeve vibration feeding disc and a flow dividing device are arranged on the outer side of the connecting sleeve feeding mechanism, a top disc containing mechanism and a top disc feeding mechanism are arranged on the outer side of the upper top disc station, an edge overturning upper punching die is arranged right above the edge overturning station, the discharging mechanism is arranged between the discharging station and the riveting pressing station, and a riveting pressing upper punching die is arranged right above the riveting pressing station. The automatic assembling machine has the advantages that the structure is adopted, automatic assembling on the lamp bracket can be achieved, the production efficiency is greatly improved, the labor strength is reduced, manpower is saved, and the production cost is low.