A method of manufacturing a low temperature polysilicon film comprises: providing a substrate on a platform; forming a buffer layer on said substrate; forming an amorphous silicon layer on said buffer layer; and heating and annealing said amorphous silicon layer to allow said amorphous silicon layer to form a polycrystalline silicon layer; wherein a thermal insulating layer is formed on a bottom surface of said substrate or a top surface of the platform, before said buffer layer is formed on said substrate.