The invention discloses an energy-saving adjustable LED lamp. The energy-saving adjustable LED lamp comprises a lamp seat shell, an outer threaded sleeve, a lamp holder assembly, slide rheostats and an adjustable electric contact assembly, wherein the lamp seat shell is provided with an electricity connecting cavity; the outer threaded sleeve is arranged on the lamp seat shell and is guided to theelectricity connecting cavity; the lamp holder assembly is in threaded connection with the outer threaded sleeve and is provided with a bulb; the slide rheostats are arranged in the lamp seat shell and are positioned on two sides; the adjustable electric contact assembly is arranged in the lamp seat shell in a built-in manner and is positioned between the slide rheostats on the two sides; by threaded adjustment on the lamp holder assembly, the bulb is driven to be close to or away from the adjustable electric contact assembly, thus, the adjustable electric contact assembly is separated form or connected with the bulb and the slide rheostats in the electricity connecting cavity, and the value of resistance of the slide rheostats is controlled. By the lamp holder assembly which is in threaded connection with the lamp, the adjustable electric contact assembly is driven by fine adjustment and is finally abutted to the slide rheostats back and forth, so that an access circuit resistance value of the slide rheostats is controlled; the brightness of the bulb is adjusted; and meanwhile, electric shock is also avoided.