The utility model discloses an illuminating lamp of a safety helmet, which comprises an illuminating lamp cap, wherein an arc groove is arranged on the lower edge of the rear side of the illuminating lamp cap, an outward protruding rotary drum is fixedly installed in the groove through a pin roll and a nut, an inverse U-shaped connection plate is installed on the axis at the two ends of the rotary drum through nuts towards the rear side, an elastic pressing plate is compressed and installed on the surface of the inner side of the front edge of the connection plate, which is higher than the surface of the rotary drum, the middle part of the lower end of the other edge of the inverse U-shaped connection plate is fixed on the outer wall of a front connector of an S-shaped hose, a battery plug and a socket are installed on a rear connector of the S-shaped hose, and a wire is connected between the battery plug and the illuminating lamp by passing through the S-shaped hose. When the illuminating lamp of the safety helmet is installed, the battery socket is fixed on the safety helmet and is communicated with a battery in the helmet, the battery plug is installed on the battery socket on the safety helmet, the lamp is shifted by hand to arbitrarily adjust the illuminating angle of the lamplight, the adjustment is flexible and convenient, and the use scope is wide.