Solar cell, preparation method thereof and laser annealing device

The invention relates to the field of photovoltaic technology, in particular to a solar cell, a preparation method thereof and a laser annealing device. The preparation method comprises the following steps: carrying out first local heating on a silicon wafer after back electrode printing; carrying out back field printing, and carrying out second local heating; positive electrode printing is carried out, and third-time local heating is carried out; in the first local heating, the second local heating and the third local heating, laser is adopted to only irradiate the grid lines for heating. In the first local heating, the second local heating and the third local heating, laser is adopted to only irradiate the grid lines for heating instead of heating the whole silicon wafer, so that not only can good ohmic contact be formed, but also the amorphous silicon film layer cannot be damaged. As good ohmic contact can be realized at high temperature, the content of the silver paste can be reduced and the production co