A laser output control device configured to control a laser oscillator which is configured to output a laser light having a pulse wave of pulses at a repetition frequency f having a duty cycle D, comprising: a pulse-width calculating section configured to calculate an ON pulse width W of the pulses during which the laser light is laser-oscillating on the basis of a laser output command used when generating an output waveform of the laser light, the ON pulse width W being calculated using the frequency f and the duty cycle D; a switching section configured to switch, on the basis of the size of the ON pulse width W, a control method to either one of peak value control, in which control is performed using a peak value of the pulse wave measured by a power sensor, and average value control, in which control is performed using an average value of the pulse wave measured by the power sensor, for calculating a current command value used for controlling the laser oscillator; a peak value command generating section (44, 45, 46) configured to generate, on the basis of an output value of the laser light output from the laser oscillator, a current command value using the peak value of the pulse wave such that the output value becomes a value that corresponds to the laser output command, when performing the peak value control on the laser oscillator; an average value command generating section (47, 48) configured to generate, on the basis of an output value of the laser light output from the laser oscillator, a current command value using the average value of the pulse wave such that the output value becomes a value that corresponds to the laser output command when performing the average value control on the laser oscillator, wherein the output value of the laser light measured by the power sensor is input to the peak value command generating section and the average value command generating section; wherein the switching section is configured to switch the control method to the peak value control when the ON pulse width W is longer than a first set time T, and is configured to switch the control method to the average value control when the ON pulse width W is equal to or less than the first set time T, wherein the first set time T is based on the characteristics of the power sensor, and the first set time T is set being equal to or larger than a time t1, t1 being a time measured from the beginning of a pulse measured by the power sensor until the pulse reaches its peak value. a pulse-width calculating section configured to calculate an ON pulse width W of the pulses during which the laser light is laser-oscillating on the basis of a laser output command used when generating an output waveform of the laser light, the ON pulse width W being calculated using the frequency f and the duty cycle D; a switching section configured to switch, on the basis of the size of the ON pulse width W, a control method to either one of peak value control, in which control is performed using a peak value of the pulse wave measured by a power sensor, and average value control, in which control is performed using an average value of the pulse wave measured by the power sensor, for calculating a current command value used for controlling the laser oscillator; a peak value command generating section (44, 45, 46) configured to generate, on the basis of an output value of the laser light output from the laser oscillator, a current command value using the peak value of the pulse wave such that the output value becomes a value that corresponds to the laser output command, when performing the peak value control on the laser oscillator; an average value command generating section (47, 48) configured to generate, on the basis of an output value of the laser light output from the laser oscillator, a current command value using the average value of the pulse wave such that the output value becomes a value that corresponds to the laser output command when performing the average value control on the laser oscillator, wherein the output value of the laser light measured by the power sensor is input to the peak value command generating section and the average value command generating section; wherein the switching section is configured to switch the control method to the peak value control when the ON pulse width W is longer than a first set time T, and is configured to switch the control method to the average value control when the ON pulse width W is equal to or less than the first set time T, wherein the first set time T is based on the characteristics of the power sensor, and the first set time T is set being equal to or larger than a time t1, t1 being a time measured from the beginning of a pulse measured by the power sensor until the pulse reaches its peak value.