A transverse vibration rolling system and a preparation method for a double-layer metal composite ultra-thin strip relate to a technical field of rolling, which solve problems including poor rolling and bonding effects, low geometric accuracy, and poor plate shape quality of metal composite ultra-thin strips. The transverse vibration rolling system includes: a first roll, a second roll, a first hydraulic vibrator, a second hydraulic vibrator, a first hydraulic motor, a second hydraulic motor, a check valve, a first hydraulic pump, a first overflow valve, an oil tank, a controller, a second overflow valve, a second hydraulic pump, an electromagnetic reversing valve, a first speed control valve, and a second speed control valve. The transverse vibration of the rolls of the present invention can apply transverse shearing force on the ultra-thin metal strips during the bond rolling.