A drive device and a drive control method for the electric bicycle are disclosed. The drive device of the electric bicycle is equipped with a power supply/storage unit, a compact motor, an inclination sensor, a brake actuation sensor, a pedal-rotating speed sensor and a drive control module. The drive device performs integrated calculations using the inclination information of the inclination sensor, the brake actuation information of the brake actuation sensor and the pedal-rotating speed information of the pedal-rotating speed sensor, so the drive control modules instructs the compact motor and the power supply/storage unit to quickly enter an auxiliary drive mode for rotating wheels of the electric bicycle, or to enter an energy recovery mode for storing electrical energy generated by the compact motor.