Abstract: Using the data of solar wind recorded by WIND and geomagnetic activity index, we studied the influence of the variation of solar wind dynamical pressure on ring current index SYM-H and auroral electrojet indexes (AU and AL). The increase and decrease of solar wind dynamical pressure can produce simultaneous or delayed disturbances in geomagnetic activity indexes, which include the transient increase of ring current index SYM-H, increase of eastward electrojet index AU and decrease of westward electrojet index AL. The sudden large increase of solar wind dynamical pressure can trigger super substorm and large geomagnetic storm. The response of geomagnetic activity indexes to solar wind dynamical pressure impulse is complicated and various, indicating the geomagnetic effect of solar wind dynamical pressure impulse not only depends on the strength and duration of solar wind dynamical pressure impulse, but also on the state of magnetosphere. Large geomagnetic storm, which last long and consume more energy, can only be triggered by strong and long impulse of solar wind dynamical pressure.