Abstract: In the teaching of electromagnetic field and wave,the finite-difference time-domain method is used to calculate and simulate the distribution of electromagnetic field and the transmission of electromagnetic wave.It can make the abstract concept intuitive and help students to study the electromagnetic field and wave teaching content.In this paper,a new unconditionally stable finite-difference time-domain(FDTD) method based on weighted Laguerre polynomials(WLPs) is studied and it is an unconditional stable algorithm with no time stability constraints,which especially suitable for the calculation of electromagnetic properties with multi-scale complex structure.The practice shows that this method is a new unconditional fast time domain algorithm.It can effectively help students to fully understand the electromagnetic field,improve the level of knowledge of electromagnetic fields.It also has a certain reference value which can help students understand the electromagnetic field numerical calculation.