The invention relates to thixotropic optical fiber filling paste for a ribbon optical cable, which mainly comprises base oil, an oil separation inhibitor, a pour point depressant, an antioxidant, an organic gelling agent, an inorganic gelling agent and a thixotropic agent. The invention also provides a preparation method for the thixotropic optical fiber filling paste for the ribbon optical cable. The thixotropic optical fiber filling paste for the ribbon optical cable is mainly characterized in that: the thixotropic optical fiber filling paste has excellent colloid stability and oxidation stability, heat resistance, weather resistance, non separation of oil in a system, low acid value, high thixotropic index, high water resistance, no emulsification, good high-temperature trickle-down property, high temperature resistance and low temperature resistance, is mainly used to be filled in a loose tube of the ribbon optical cable so as to prevent water or other fluid from flowing into or moving into the optical cable, and provides excellent effects of resisting water, buffering and the like for the optical cable.