Sorry, I cannot input chinese here.
These photos have no fancies but try to explain how to produce white background by flash, instead of PS. Yeah, flashes can produce pure white and black background without any PS.
This is done in my basement studio. Two strobes: 250w with large softbox for the white backdrop (DIYed from floor vinyl) 110 W with large softbox to fill. Small speedlight for faces or eyes. No working photos this time, maybe next time.
And they are my two daughters...