Qiong Kiln began to make oil-efficient lamp from the Tang Dynasty. Despite its appearance, it has been praised by poets for hundreds of years since its inception. It has a double calyx with a handle. Oil is held in the flat arc lamp surface, and water is injected into the double calyx from a short mouth in the front. The cold water in the double calyx lowers the temperature in order to save oil. It is a kind of convenient and oil-feeicient lamp with genuine scientific value.