Thorium(IV) complexes of bis-Schiff bases containing 2,6-pyridinediamine were synthesized by grinding solid phase synthesis method with salicylaldehyde, O-vanillin，2,6-pyridinediamine and thorium nitrate as base materials. The structures and composition were characterized by elemental analysis, method of EDTA titration, infrared spectrum, ultraviolet spectrum and TG-DTA analysis. The experimental results demonstrated that the thorium ion is coordinated through the Schiff base ligands as terdentate with O, N from phenolic, imino groups, and nitric acid root respectively. The coordination number of thorium ion is eight.