The Miller cycle effect was achieved with continuous variable valve lift (CVVL) on a 1.5L turbocharged direct injection gasoline engine through bench test. The pumping loss, mechanical loss, theoretical thermal efficiency, and the relationship between Miller cycle and LP-EGR were further studied and the optimized scheme was proposed and analyzed. The experimental results show that the CVVL technology realizes the Miller cycle effect, the pumping loss and mechanical loss reduce to a certain extent, the combustion efficiency improves, but the fuel consumption reduction is not obvious. By increasing the compression ratio of engine and matching the LP-EGR system, the effect of EGR on fuel consumption reduction becomes obvious and the Miller cycle effect relatively weakens. The EGR requirement of engine aeration-enhancing ability results in a certain decrease of Miller degree.