A plant-growing device with light emitting diode comprises a darkroom, a generator, a gas collecting device and a water supplying device. The darkroom comprises an accommodating space and a plurality of light emitting diodes disposed in the accommodating space for producing a light beam irradiating the accommodating space. The generator is disposed outside the darkroom. The generator is configured to receive sunlight from the atmospheric environment and convert it into an electric energy and provide the electric energy for the light emitting diodes. The gas collecting device connected between the accommodating space and the atmospheric environment is configured to transfer carbon dioxide from the atmospheric environment into the accommodating space and discharge oxygen from the accommodating space into the atmospheric environment. The water supplying device connected to the darkroom is configured to transport water outside the darkroom into the accommodating space.
