Based on the selfdeveloped electrohydraulic variable valve system, the influence of key parameters on transient change of electrohydraulic variable valve lift curve was studied. The characteristic points were used to describe the characteristic changes of valve lift curve to provide theoretical support for parameter selection. The research results show that there is a critical value for the influence of fuel intake phase on characteristic phases of β_d and β_g and the characteristic phases advance with the increase of fuel supply pressure. Meanwhile, the characteristic phase of  β_d is not affected by the oil discharge phase, but the oil discharge phase affects the characteristic phase of  β_d with an inflection point. Both the characteristic phases of  β_g and β_g delayed with the increase of speed.