The invention discloses a convective heat loss LED lamp which comprises a radiator. A semispherical connection portion protruded outwards is integrally formed at the center position of the upper end of the radiator. A PCB is arranged on the outer side of the semispherical connection portion. LED lamp beads are arranged on the PCB. The upper end of the radiator is provided with a lens. The lens comprises a cone-frustum-shaped lens body. A semispherical slot is formed in the lower portion of the cone-frustum-shaped lens body. Multiple spherical segment-shaped light feeding grooves are evenly distributed in the cone-frustum-shaped lens body and located in the semispherical slot. A cone slot is formed in the upper end face of the cone-frustum-shaped lens body. The lower end of a radiation barrel is provided with a connection portion. The connection portion is provided with multiple radiation holes capable of penetrating through the connection portion in the axis direction of the radiation barrel. An exhaust fan device capable of supplying air into the radiation holes and a cavity inside the radiator is connected to the connection portion. The convective heat loss LED lamp is good in radiation effect and long in service life.