The invention discloses an assembling machine with a transistor automatically sleeved with a magnet ring. The assembling machine comprises a machine frame, a transistor vibrating disc feeding device, a magnet ring vibrating disc feeding device, a linear moving mechanism, a magnet ring sleeve device and a gluing device. The linear moving mechanism comprises a fixed board, a movable board and a movable material duct, wherein a first driving mechanism is arranged and corresponds to the movable material duct, a first locating groove is formed in the fixed board, a second locating groove is formed in the movable board, and a second driving mechanism is arranged and corresponds to the movable board. Therefore, the function of being automatically sleeved with the magnet ring is achieved by utilizing the linear moving mechanism to convey the transistor and utilizing the magnet ring sleeve device and the gluing device to install and fix the magnet ring on a pin of the transistor in a sleeved mode, operation efficiency can be effectively improved, due to the matched arrangement of the first locating groove and the second locating groove, the transistor can be well located in the process of being sleeved with the magnet ring and glued, excursion will not occur, errors of assembling positions are avoided, the accurate assembling positions are ensured, and accordingly the assembling quality of products can be improved.