DC accelerating aging characteristics of praseodymium-based ZnO varistors doped with $Dy_2O_3$ were investigated with sintering time. The varistor sintered for 1h exhibited the highest nonlinearity, with a nonlinear exponent of 66.61 and a leakage current of $1.16{\mu}A$, whereas they did not exhibit relatively high stability. The varistor sintered for 2h having nonlinear exponent of 54.81 and leakage current of $2.52{\mu}A$ showed very excellent stability, which the variation rates of varistor voltage, nonlinear exponent, and leakage current are -1.19%, -4.00%, and +75.79% for 2h, under DC accelerated aging stress, such as ($0.85\;V_{1mA}/115^{\circ}C$/24h)+($0.90\;V_{1mA}/120^{\circ}C$/24h)+($0.95\;V_{1mA}/125^{\circ}C$/24h)+($0.95\;V_{1mA}/150^{\circ}C$/24h).