The transient dose rate effect of the DC/DC converter based on PWM controller with feature of 0.35 μm was studied under pulsed laser. The DC/DC converter was irradiated by a laser with spot diameter of 10 mm, wavelength of 1 064 nm, pulse width of 10 ns and energy from 3 μJ to 2 400 μJ. The responses of DC/DC converter under different energy laser were monitored and compared with the experimental results of pulsed γ-ray. The experimental results show that the output disturbance time of DC/DC converter is about 4.3 ms under the 3 μJ to 577 μJ laser and the output locking threshold of DC/DC converter is about 1 031 μJ.