Shell heat dissipation type down lamp

The down lamp comprises a lamp body and an installation box provided with a lamp body installation hole, the lamp body comprises a cylindrical panel, a radiator connected to the panel, a reflection cup connected in the radiator and provided with a downward opening, an LED light source connected to the upper end of the reflection cup and a hanging structure connected with the panel, the radiator is arranged in a lamp body mounting hole in a penetrating mode and hung through a hanging structure, the LED light source is connected with the upper end of the radiator in a heat conduction mode, an expansion section is arranged at the upper end of the radiator, a plurality of cooling fins are arranged on the outer surface of the expansion section, and the outer surface of the lamp body is formed by the outer surface of the radiator and the outer surface of the expansion section. A power line of the LED light source is connected with a switch for controlling the power channel, the switch is located in the upper end of