The electrode pattern of the optimal design for the solar cell can get the high photoelectric conver. sion efficiency. The optimal design of the screen-printed electrode in the crystalline silicon solar cell is introduced with the example, and the relation among the power loss in the solar cell, the diffusion sheet resistance and the width of the thin grid line is discussed. On the basis of the original design, the ideal solar cell grid line is designed. The optimal solar cell can reduce the total power loss caused by the electrode design, and increase the photoelectric conversion efficiency of the cell.