The utility model discloses an automatic assembling machine. The utility model belongs to the technical field of assembly equipment, the device comprises a magnetic ring feeding tray, tray dischargingmechanism, the magnetic ring carries the left-right moving motor; the magnetic ring carrying up-and-down moving cylinder; the magnetic ring assembling machine comprises a magnetic ring sucking up-down moving air cylinder, a jig feeding mechanism, a bottom plate feeding vibration disc, a bottom plate feeding straight vibrator, a bottom plate correcting air cylinder, a magnetic ring correcting aircylinder, a jig returning belt motor, a magnetic ring sequencing correcting air cylinder, a magnetic ring feeding conveying motor, a jig returning magnet ring adjusting conveying belt, a bottom plateassembling mechanism, a magnetic ring assembling mechanism, a control box body and an assembling groove. A detection optical fiber is mounted at each of the feeding, pushing and sucking positions; theautomatic assembling machine has the advantages that the automatic assembling machine is simple in structure, does not act when materials do not exist, has a shutdown alarm function when materials are full or clamped, adopts a magnetic ring tray uninterrupted feeding mode, has an empty tray automatic discharging function, a high-precision servo control system and a flexible magnetic ring assembling function, avoids poor magnetic ring collapse, and can realize automatic assembling through the bottom plate assembling mechanism and the magnetic ring assembling mechanism.