A lighting fixture includes a lamp support, a lamp arm on the lamp support, a lamp cup shell defining an installation seat at an end of the lamp arm, a lamp shade configured to be supported on the lamp cup shell, and an LED bulb configured to extend into the installation seat. The LED bulb includes a heat sink, an LED lamp panel on the heat sink including LEDs on a base board, a light transmitting cover covering the LED lamp panel, a bottom case assembly on the heat sink including an LED power drive module electrically coupled to the LED lamp panel, and electrical connection members for electrically coupling the LED bulb to the lamp cup shell. A screw press ring is configured to attach the LED bulb to the lamp shade, and mechanical installation members are configured to detachably couple the LED bulb to the lamp cup shell.