A lighting lamp includes a light guide board, which is directly mounted in the cavity of a lamp holder, furniture, utensil, or the construction of a building, having a clear transmissive layer at the front side and a continuous piece of reflective layer a clear transmission layer at the front side and a reflective layer at the back side that has the shape of an umbrella surface and sloping from the periphery toward its center, and a plurality of LEDs mounted within the cavity outside the light guide board and controlled to emit light laterally into the inside of the light guide boards to provide a uniform lighting effect having an enhanced brightness without multi-image and to simulate the lighting effect of a ball lamp.