The invention provides lead-free positive silver paste applied to a silicon solar cell. The lead-free positive silver paste is a mixture of micron silver powder, an organic binder and an inorganic additive. The inorganic additive is formed by coating the surface of submicron silver powder with tellurium bismuth alkali metal glass, and pyroceram particles of silver crystal grains are precipitated on the tellurium bismuth alkali metal glass. The preparation process comprises the steps that the submicron silver powder is dispersed in the aqueous solution of polyvinyl alcohol to form a suspension; the compound of tellurium, bismuth, alkali metal, silicon, magnesium barium strontium and zinc and the like and the mixed aqueous solution of boric acid are added; atomization is carried out; atomized droplets fall into deionized water through a vertical heating tube and are cooled to acquire the inorganic additive; and the inorganic additive, the micron silver powder and the organic binder are mixed and three-roll dispersed. According to the invention, the positive silver paste is lead-free and environment-friendly, and has excellent ohmic contact; and the conversion efficiency of a silicon solar cell sheet can be remarkably improved.