The utility model provides a light electric bicycle, and relates to an electric bicycle which can be used electrically and manually. The light electric bicycle comprises a handlebar, a front fork, a front wheel, a pedal transmission component, a supporting frame, a lower beam, a rear wheel, a rear bicycle seat, a saddle, a lower beam, a motor transmission component, a controller, a storage battery, a motor and a control handle arranged on the handlebar. The pedal transmission component is arranged on the lower beam on one side of the rear wheel, the motor transmission component is arranged on the other side, opposite to the side where the pedal transmission component is located, of the rear wheel, the motor is fixed on the supporting frame between the saddle and the rear bicycle seat, and the output end of the motor is arranged on the same side with the motor transmission component. The controller, the storage battery and the motor are connected with the control handle through wires. The two sides of the light electric bicycle are respectively provided with a set of transmission system, the transmission systems are connected through a chain, manpower and the motor are combined to drive the bicycle to run, driving forces are independent without being interfered by each other, and a rider can easily ride the bicycle.