In this contribution, we report AMPT model study for the hyperon global polarization in heavy ion collision, especially interesting Ô (1 ~ 10) GeV energy region. We find a non-monotonic trend, with to first increase and then decrease when beam is lowered from 27 down 3 GeV, maximum signal located around √ S NN = 7.7 GeV. addition, local patterns are also computed same regime.