To fully study the temporal evolution mechanism of strong magnetic fields in laser-induced plasma, the mechanism of strong magnetic field generation in laser-induced plasma is investigated. By analyzing the mechanism of laser plasma interaction, the coupling frequency of incident and scattered light generated by multi light nonlinear Compton scattering and strong magnetic field during their interaction is analyzed, and the induction mechanism of strong magnetic field in laser-induced plasma is obtained. Under the induction mechanism, the magnetic field strengths of the strong magnetic field temperature gradient and density gradient are calculated when they are distributed in the strong magnetic field space, so as to obtain the specific temporal evolution mechanism of the distribution of the two in the strong magnetic field space. Specific application experiments show that the two mechanisms are verified by calculating the changes in the ion current density component and the distribution of electron density, and the entropy value results in 0.28 under the current fluctuation conditions, which has high stability.