A tandem pulse arc welding control apparatus in which a pulse cycle for a first welding wire and a pulse cycle for a second welding wire insulated from the first welding wire are synchronized with each other, the tandem pulse arc welding control apparatus comprising: voltage detection means for detecting a voltage at the second welding wire, and for outputting a value of the voltage detected at the second welding wire; voltage-target-value setting means for outputting a voltage target value, which is set in advance, for the second welding wire; pulse-peak-output-reference-value setting means for outputting a pulse-peak-output reference value, which is set in advance, for the second welding wire; pulse-base-output-reference-value setting means for outputting a pulse-base-output reference value, which is set in advance, for the second welding wire; characterised in that: output-variation-value calculating means for calculating a pulse-peak-output variation value for the second welding wire and a pulse-base-output variation value for the second welding wire on the basis of a difference between the value of the voltage detected at the second welding wire and the voltage target value for the second welding wire; pulse-peak-output-value calculating means for calculating a pulse-peak-output value for the second welding wire by adding the pulse-peak-output variation value for the second welding wire to the pulse-peak-output reference value for the second welding wire; pulse-base-output-value calculating means for calculating a pulse-base-output value for the second welding wire by adding the pulse-base-output variation value for the second welding wire to the pulse-base-output reference value for the second welding wire; second pulse-waveform selection means, into which a pulse cycle signal indicating whether the first welding wire is in a pulse peak period or a pulse base period is input, for outputting the pulse-peak-output value for the second welding wire when the pulse cycle signal indicates the pulse peak period, and for outputting the pulse-base-output value for the second welding wire when the pulse cycle signal indicates the pulse base period; and output control means for controlling an output value for the second welding wire on the basis of the pulse-peak-output value for the second welding wire and the pulse-base-output value for the second welding wire, which have been output by the second pulse-waveform selection means. voltage detection means for detecting a voltage at the second welding wire, and for outputting a value of the voltage detected at the second welding wire; voltage-target-value setting means for outputting a voltage target value, which is set in advance, for the second welding wire; pulse-peak-output-reference-value setting means for outputting a pulse-peak-output reference value, which is set in advance, for the second welding wire; pulse-base-output-reference-value setting means for outputting a pulse-base-output reference value, which is set in advance, for the second welding wire; output-variation-value calculating means for calculating a pulse-peak-output variation value for the second welding wire and a pulse-base-output variation value for the second welding wire on the basis of a difference between the value of the voltage detected at the second welding wire and the voltage target value for the second welding wire; pulse-peak-output-value calculating means for calculating a pulse-peak-output value for the second welding wire by adding the pulse-peak-output variation value for the second welding wire to the pulse-peak-output reference value for the second welding wire; pulse-base-output-value calculating means for calculating a pulse-base-output value for the second welding wire by adding the pulse-base-output variation value for the second welding wire to the pulse-base-output reference value for the second welding wire; second pulse-waveform selection means, into which a pulse cycle signal indicating whether the first welding wire is in a pulse peak period or a pulse base period is input, for outputting the pulse-peak-output value for the second welding wire when the pulse cycle signal indicates the pulse peak period, and for outputting the pulse-base-output value for the second welding wire when the pulse cycle signal indicates the pulse base period; and output control means for controlling an output value for the second welding wire on the basis of the pulse-peak-output value for the second welding wire and the pulse-base-output value for the second welding wire, which have been output by the second pulse-waveform selection means.