Disclosed is a method for preparing a sheet for a sealing member of a solar cell, wherein the sheet has significantly low thermal shrinkage and high flexibility, and a superior capability of discharging bubbles during the manufacture of a solar cell module. The method for preparing a sheet for a sealing member of a solar cell according to the present invention comprises the following steps: (a) preparing a thermal adhesive resin having an olefin-based resin as a main component; (b) pulverizing the thermal adhesive resin and dispersing the resin powder; and (c) heating the thermal adhesive resin powder at a temperature lower than the melting temperature of the resin powder so as to prepare a sheet having a plurality of voids.