Abstract: Provided are a solar cell sheet and a heat treatment process thereof The heat treatment process includes: a) sifting from solar cell sheets after printed and sintered cell sheets with conversion efficiency lower than 18% and filling factor thereof higher than 70%; h) performing low temperature annealing on the sifted cell sheets; c) sifting from the cell sheets after low temperature annealing cell sheets with lowered filling factor; d) re-sintering the sifted cell sheets; and e) sifting from the re-sintered cell sheets cell sheets with conversion efficiency lower than 18% and returning back to b) until most or all of the sifted meet demands.