This work studies the nonlinear Thomson scattering and its radiation properties when electrons interact with linear polarization lasers using a single electron model. By theoretical derivation and program simulation, electron motion trajectories at different initial phases are mirror symmetrical at 180◦ intervals. The influence of the initial phase of linear polarization laser pulse on the spectrum of high energy electron radiation is analyzed. Simulation results reveal that the radiation spectrum of high energy electrons at different phases has periodic symmetry, and the frequency of the peak of the spectrum decreases with the increase of the initial phase in one period. The peak value and the oscillation amplitude of the two-dimensional spectrum decrease with the increase of the initial phase and the energy distribution of the spectrum moves to the high frequency region with the increase of the initial phase. In addition, the electron radiation characteristics undergo a mutation when the initial phase changes in the range from 135◦ to 150◦. Based on the above simulation results, it provides theoretical guidance for further numerical simulation and study of high-energy electron radiation under linear polarization laser.