An LED lamp with an adjustable illuminating range is provided, including a lamp body. The lamp body includes a base, a lamp housing arranged on the base, and a light source assembly arranged inside the lamp housing. At least one side of the lamp housing includes an open structure allowing light from the light source assembly to emit. An adjusting mechanism is configured inside the lamp housing to adjust the illuminating range of the light emitted from the light source assembly. An emergence angle of the light source assembly or a size of the opening structure can be adjusted by the adjusting mechanism, thereby adjusting the illuminating range or an illuminating area of emitted light and meeting different user demands.