Ask a photographer, how much W power and how many W bulbs does the fill light of SLR camera need to shoot at night?

Fill the light? Just shoot with a fill light, just shoot with a flash, and a hot shoe flash can also be used to flash off the plane. If you have to use a long bright constant light source, it has nothing to do with wattage. The bigger the wattage, the better. The exposure during shooting depends on your aperture shutter setting. What matters is the size of the shape of the light source, that is, the coverage of the light, which needs to be determined according to your subject. If you shoot the city scenery at night, it seems that it doesn't matter how much fill light you use, in fact, it won't work either. The focus is on the setting of aperture and shutter.