Abstract: A combination buddy bicycle includes a front bike frame, two transverse frames, two front wheel brackets, two steering control bar, front and rear transmission shafts, 1st˜4th pedal assemblies, a middle bike frame, a rear wheel transmission shaft, a rear bike frame, two rear transverse frames, and two rear wheel brackets. The rear bike frame can be directly connected to the front bike frame after removal of the middle bike frame, enabling the bicycle to be ridden by two persons side by side. When the steering control bars are biased, the connected front wheel brackets and front wheels are synchronously biased, assuring high stability.