In order to study the radiation energy distribution of laser pulse width after impact electron, the method of simulation calculation was adopted. Based on Lorentz equation and electron radiation equation, a single electron model of compact focusing laser acting on static single electron was established. The distribution of electron radiation energy produced by laser pulse and electron action under different pulse width was simulated by MATLAB software. The pulse width of femtosecond compact focusing elliptic polarization laser pulse and the peak radiation power between electrons were studied. The simulation results show that when the compact focused laser pulse encounters a stationary single electron, the electron radiates while the laser pulse hits the electron. The scattering radiation accumulates in a sharp cone at the center of the scattering direction. With the increase of laser pulse width, the distribution of radiation power gradually presents a double peak. The wider the pulse width, the smaller the peak value of electron radiation power. When the pulse width is 10λ0, the peak power is only 1% of that when the pulse width is 0.1λ0, and the initial pulse width is λ0=3.33fs. At the same time, the wider the pulse width, the smaller the peak value of the electronic radiation power, the longer the required realization of the peak radiation power, the longer the duration of the peak, the lower the cut-off frequency of the spectrum function, the less high frequency components, and the increase of the harmonic frequency. The results are of great significance to the diagnosis of laser air plasma.