2,3,5,6-tertraaminopyridine-2,5-dihydroxy terephthalic acid was synthesized through neutralization reaction by using 2,3,5,6-tetraaminopyridine(TAP) hydrochloride and 2,5-dihydroxy terephthalic (DHTA) as raw materials. PIPD was polymerized from TD salt by condensation polymerization. The effect of various reaction parameters on polymerization, including the type of monomer, reaction time, additional amount of monomer and molar ratio of reactants was investigated in detail. The optimal reaction conditions were confirmed: the molar ratio of DHTA and TAP hydrochloride was 1.05：1. Additional amount of TAP hydrochloride was 0.5%wt of TD salt and added at 140 ℃, and then the reaction proceeded at 180℃ for 3.5 h. Compared with existing processes，the relative viscosity for characterizing the molecular weight of PIPD by this way increased approximately twice.