Valve lift conversion control mechanism and valve system of engine

A valve lift conversion control mechanism applied to a valve system of an engine, comprising a hydraulic transmission device, a check valve and a solenoid valve, wherein

• the hydraulic transmission device comprises at least two device bodies that are in communication with each other through an oil circuit;
• the solenoid valve is configured to supply oil to the oil circuit through the check valve;
• and
• the oil in the oil circuit is pressed in a case that a second device body of the hydraulic transmission device is pressed downwards by a second rocker arm of the valve system and an oil pressure is increased, and a first device body of the hydraulic transmission device presses a first valve controlled by a first rocker arm of the valve system downwards under the oil pressure in the oil circuit which is increased.