A new binuclear nickel(II) complex Ni₂(HPT)₄(H₂O)₃ (1) has been hydrothermally synthesized with nickel hydroxide, 3,4-pyridine dicarboxylic acid and 3-(pyridin-2-yl)-1,2,4-triazole (HPT) in the mixed solution (the volume ratio of methanol and water is 1:4). It crystallizes in tetragonal space group P4₂/n, with a = 20.844(1), b = 20.844(1), c = 7.2463(7) Å, V = 3148.2(5) ų, D_c = 1.587 g/cm³, Z = 4, μ(MoKa) = 1.257, F(000) = 1544, the final GOOF = 1.043, R = 0.0437 and wR = 0.1297. The crystal structure shows that the whole molecule consists of two nickel ions which are bridged by four μ₂-η¹:η⁰-3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Ni(II) ion is NiN₆, giving a distorted octahedral geometry. The thermal stability and fluorescent and magnetic properties of the complex were investigated.