Shock compression properties of polyethylene (CH2) were studied at SG-Ⅱ laser facility. The experimental results show that the self-emission is high,which emits from the shock-front in polyethylene. And the shock-front propagates through the polyethylene step almost with constant velocity. The Hugoniot equation of state (EOS) of polyethylene was measured by using the impedance-matching method with aluminum as standard material. Pressures are high up to 0.54 TPa in polyethylene, and the relative expanded uncertainties of the measured shockwave velocity are about 2% (K=2). Moreover, the consistency of our data is good, and our data are also consistent with existing experimental data and EOS model.