Disclosed are a method and an apparatus for manufacturing low temperature poly-silicon film, and a low temperature poly-silicon film. The method includes: providing a substrate; forming an amorphous silicon film; applying different temperatures to different regions of the amorphous silicon film by using an excimer laser annealing method, to change the amorphous silicon film into a molten state; and recrystallizating the amorphous silicon film in the molten state, a region having a lower temperature serving as a starting point, a region having a higher temperature serving as an end point, to form a low temperature poly-silicon film. The low temperature poly-silicon film manufactured by the above method and apparatus has a greater size of the crystalline grain and a larger electronic mobility than in the existing technology.