The invention discloses an energy-saving light-emitting diode (LED) panel lamp, which comprises an aluminum frame, a diffusion plate, a light guide plate, a reflecting film, an aluminum back panel, LED lamp beads and aluminum-based circuit boards, wherein the LED lamp beads are welded on the aluminum-based circuit boards and are inserted into grooves of the aluminum frame; the aluminum frame has the length of 1,500 to 1,800mm and the width of 610 to 690mm; a plurality of radiating ribs are arranged on the outer side of the aluminum frame; the upper end face of the aluminum frame is provided with dovetail grooves; the dovetail grooves are provided with conical screws; the reflecting film covers the reflecting surface of the light guide plate; double-faced adhesive tapes are adhered to the peripheries of the diffusion plate, the light guide plate and the aluminum back panel; every two of the diffusion plate, the light guide plate and the aluminum back panel are sequentially connected to form a whole; and the diffusion plate, the light guide plate and the aluminum back panel are integrally arranged in the groove of the aluminum frame. The energy-saving LED panel lamp is large in luminous area and low in power, achieves an enough and proper illumination effect, has the function of saving energy and suitable for energy-saving illumination in special small spaces such as elevators and toilets; and moreover, the energy-saving LED panel lamp is good in radiating effect, low in fault rate and convenient to mount, and the service life of the LED is prolonged.