A downlight apparatus includes a downlight housing, a drawstring module and a light module. The downlight housing has a surface rim and a downlight holder. The surface rim defines a rim opening. The surface rim conceals an installation cavity. The holder defines a holder space connected to the rim opening. The downlight housing is attached in the installation cavity with a fixing unit. The drawstring module is used for collecting a pullable wire. The pullable wire is electrically connected to a power source. The light module has a light source and a light housing. The light housing is connected to a bottom end of the pullable wire for electrically connecting the power source to the light source. The light module is pulled out from the holder space to an adjustable distance from the rim opening with the pullable wire connecting the light module to the downlight housing.