Based on the two-fluid dynamics equations describing plasma flow in a cold magnetized medium

the propagation of Alfvén waves initialized by a one-period-time field-aligned current at the top of the low-latitude ionosphere has been stimulated

the reflection and coupling of Alfvén wave in the low-latitude ionosphere has been analyzed.The results show the reflection coefficient is larger at the bottom end of resonator

and the shear wave is reflected distinctly（reflection coefficient（R）≥0.6）.If wave frequency is approximately equal to the cavity mode frequency

compressional Alfvén wave that propagates across background magnetic field lines is generated while reflection occurs

then the disturbed magnetic field has effect to the local geomagnetic pulsations.And the results prouide a scientific warranty to explain the phenomena of the geomagentic pulsations.