The invention discloses an electro-hydraulic variable valve device with an energy accumulator buffer function. The electro-hydraulic variable valve device consists of an oil supply loop and an energy accumulator loop which are connected with an engine valve actuating mechanism, wherein the oil supply loop consists of an oil tank, a first overflow valve, a motor, an oil pump and a three-position four-way electromagnetic valve; the three-position four-way electromagnetic valve is a U-shaped meso-position function electromagnetic valve; and the energy accumulator loop consists of a hydraulic cylinder, an energy accumulator, a one-way valve and a second overflow valve. By controlling the reversing of the electromagnetic valve, a valve spring and the energy accumulator can absorb energy when the valve ascends; the valve spring and the energy accumulator release energy in the falling process; and during seating, the valve spring releases energy and the energy accumulator absorbs energy, so that a motion characteristic of accelerated ascending, slow ascending, accelerated descending, slow descending and sable seating of the valve is realized finally. The electro-hydraulic variable valve device has an effective buffer function when the valve is positioned at the maximum lift position and a sealing position, and has the effect of reducing energy consumption. Compared with the traditional hydraulic variable valve actuating mechanism, the electro-hydraulic variable valve device has the advantages of simple structure and simple control.