Ball lightning is widely concerning because it is hard to detect,predict,and reproduce.The dependences of electromagnetic[EM]solitons,which are considered expectant ball lightning,forming at the wavelength of the incident light are investigated with two-dimensional particle-in-cell simulations.It shows that both the long wavelength microwave and the short wave-length laser are not suitable for producing the observed ball-lightning-like EM solitons.A strong field terahertz wave is proposed to inject and generate EM solitons.This paper can provide some references for researchers studying ball lightning.