For the problem of high combustion pressure near the rated operating point of highly intensified diesel engine, Miller cycle can be realized by increasing the late closing angle of intake air, which can decrease the temperature and pressure at the end of compression and effectively control the combustion pressure, but will also decrease the effective compression ratio and bring about the problem of difficult starting. Using two-stage variable valve technology, ideal working environment can be obtained under both starting and rated conditions. A two-stage variable valve train was hence designed. Compared with the traditional variable valve train technology, the two-stage electro-hydraulic variable valve technology could control the opening and closing of solenoid valve to switch the valve lift and phase by designing the two-stage camshaft and switching mechanism, which had the advantages of rapid response, accurate control and independent working process. The simulation and experiment of motion control and the influence rule analysis were further conducted. The results show that the fuel pressure has a great influence on the switching speed and the fuel pressure beyond 0.12 MPa will make the switching process stable. And the greater the fuel pressure, the faster the switching response. Besides, engine speed has little effect on switching.