Abstract: The invention relates to a tube-in-tube LED tube, which comprises a tubular plastic lampshade, two caps connected to power supply is separately defined at the two ends of the tubular plastic lampshade, a LED lamp board is defined inside the tubular plastic lampshade sheathed with a glass tube and two ends of the glass tube is separately connected to the two caps. In case of the glass tube broken, the tubular plastic lampshade can still protect the LED lamp board from being damaged. By the way, the tube-in-tube LED tube has properties of high safety, uniform illumination, larger illumination range, simple structure, and easy to manufacture and maintenance. Also the LED lamp board is embedded into the slots in the inner wall of the tubular plastic lampshade, resulting in convenient and quickly installation, and material saving.