NOVELTY - A solar battery back slurry comprises 45-60 wt.% metal powder, 1-6 wt.% lead-free glass powder, 31-46 wt.% organic adhesive and 0-3 wt.% auxiliary agent, where the metal powder comprises silver powder, the lead-free glass powder comprises 50-85 wt.% bismuth oxide, 1-25 wt.% zinc oxide, 1-10 wt.% boron trioxide, 1-5 wt.% aluminum trioxide, 1-5 wt.% barium oxide, 1-3 wt.% silicon dioxide and 0-2 wt.% antimony trioxide.    USE - Solar battery back slurry.    ADVANTAGE - The solar battery back slurry has excellent electric conductivity, low series resistance and high photoelectric conversion efficiency, and improves adhesive force between back electrode and silicon chip and forms good ohmic contact with silicon chip.    DETAILED DESCRIPTION - A solar battery back slurry comprises 45-60 wt.% metal powder, 1-6 wt.% lead-free glass powder, 31-46 wt.% organic adhesive and 0-3 wt.% auxiliary agent, where the metal powder comprises silver powder, the lead-free glass powder comprises 50-85 wt.% bismuth oxide, 1-25 wt.% zinc oxide, 1-10 wt.% boron trioxide, 1-5 wt.% aluminum trioxide, 1-5 wt.% barium oxide, 1-3 wt.% silicon dioxide and 0-2 wt.% antimony trioxide, the organic adhesive comprises 1-15 wt.% organic carrier and 5-98 wt.% organic solvent, and the auxiliary agent is ferric oxide, zinc oxide, titanium oxide, nickel oxide, or selenium telluride. An INDEPENDENT CLAIM is also included for a method for preparing the solar battery back slurry, which involves weighing and heating lead-free glass powder at 900-1300 degrees C, maintaining temperature for 30-50 minutes, grinding the mixture for 40-50 hours, filtering the mixture with 200 mesh, drying the mixture at 80-110 degrees C to obtain glass powder with average particle diameter of 3 mu m, weighing organic carrier and organic solvent, heating the organic carrier and organic solvent, maintaining temperature at 50-100 degrees C, dissolving surfactant in the mixture, maintaining temperature for 5-15 minutes, filtering the mixture, weighing metal powder, adding metal powder and organic adhesive agent to the mixture, adding auxiliary agent to the mixture, grinding the mixture to obtain the solar battery back slurry with granularity of 5 mu m and viscosity of 290-380 Pa.