A manufacturing method of a polycrystalline solar cell is disclosed. A polycrystalline silicon solar cell in accordance with the present invention performs crystallization-annealing amorphous silicon with a metal catalyst so as to reduce a crystallization temperature. The manufacturing method of a solar cell in accordance with the present invention includes the steps of (a) forming a first amorphous silicon layer on a substrate; (b) forming a second amorphous silicon layer on the first amorphous silicon layer; (c) forming a metal layer on the second amorphous silicon layer; (d) performing crystallization-annealing the second amorphous silicon layer; and (e) forming a third amorphous silicon layer on a resulting crystalline silicon layer of the step (d).