Abstract: The present invention relates to a reflecting cap for enhancing an illuminance of an illumination, which can enhancing the illuminance, protect skin by UV blocking, prevent dazzling, used with being inserted on lamp of various existing illuminations and adjust an irradiation angle of the light freely. To this end, the present invention provides a reflecting cap for enhancing an illuminance of an illumination, which includes a sheet having a shape that is inserted on a lamp of an illumination so as to enhance an illuminance of the illumination. In accordance with the present invention, an illuminance is increased and an economic effect can thus be expected. Further, it is possible to adjust an irradiation angle of the illumination light by adjusting an angle of the sheet inserted on the lamp of the illumination.