A lamp with functions of adjusting an illumination direction is disclosed. A substrate is disposed on a base and includes a through groove. At least one light source is disposed on the substrate. An electronic control unit is disposed in the base. A telescopic member is disposed in the base and is connected to the electronic control unit. The electronic control unit drives the telescopic member to elongate and shorten. A flexible light guiding sheet is connected to the telescopic member. When the electronic control unit drives the telescopic member to elongate, the flexible light guiding sheet protrudes onto the substrate via the through groove of the substrate and deflects toward a specific direction, changing the illumination direction of the light source.