Under the frame of quantum electrodynamics, by using a nonperturbative quantum scattering theory, photodetachment of ions in ultrafast strong laser fields was investigated. It was found that for the same above-detachment peaks, with the cycle number and carrier-envelope phase constant, when ions with γ times of binding energy were irradiated by γ times of frequency and γ3 times of laser intensity, angular distributions of photoelectrons didn’t change, where γ was arbitrary positive real number. The results verifies the scaling law of photoionization in few-cycle laser pulses.