The present invention discloses an elastic heat spreader for chip packaging, a packaging structure and a packaging method. The heat spreader includes a top cover plate and a side cover plate that extends outward along an edge of the top cover plate, wherein the top cover plate is configured to be placed on a chip, and at least a partial region of the side cover plate is an elastic member; and the elastic member at least enables the side cover plate to be telescopic in a direction perpendicular to the top cover plate. According to the present invention, a following problem is solved: delamination between the heat spreader and a substrate as well as the chip due to stress generated by different thermal expansion coefficients of the substrate, the heat spreader and the chip in a packaging process of a large-size product.