The invention discloses an LED lamp automatic assembling machine which comprises a machine frame, a first assembling line, a second assembling line and a third assembling line. The first assembling line is used for assembling a light emitting assembly, the second assembling line is used for assembling a lamp holder and the light emitting assembly, and the third assembling line is used for installing a lamp shell. The first assembling line, the second assembling line and the third assembling line are arranged on the machine frame. The first assembling line comprises a conveying belt, a first conveying disc, a first mechanical hand and a first pressing mechanism. The second assembling line comprises a second conveying disc, a second mechanical hand, a lamp holder vibration disc, a lamp holder mechanical hand, a rivet vibration disc, a rivet mechanical hand and a riveting assembly, and the third assembling line comprises a third mechanical hand, a lamp shell vibration disc, a lamp shell mechanical hand, a pressing assembly and an unloading device. By means of the arrangement, the parts can be automatically assembled into an LED lamp finished product only by being placed into corresponding containers, the LED lamp is automatically assembled, manual operation is reduced, production efficiency is improved, and the labor cost is saved.