Chinese Sheldon is a Chinese version of Sheldon Cooper.
He appears in the final scene of "The Cooper-Hofstadter Polarization" where he and Chinese Leonard watch Howard's uploaded YouTube video of Leonard and Sheldon fighting at Leonard's presentation.
Howard - or Wolowizard - then uses the Internet to switch their lights on and off.
It's unknown if he is really like Sheldon in terms of personality, given that he only makes a cameo appearance and that he is only dressed as Sheldon.