The invention provides an
engine valve mechanism motion characteristic test method which comprises the following steps: S1, forming a mounting space in the cylinder body of an engine, arranging a
laser displacement sensor in the mounting space, wherein the
laser displacement sensor opposes the air valve of the valve mechanism, and the
laser displacement sensor is used for measuring valve displacement of the
engine valve mechanism; S2, driving the engine to operate through external
power equipment, and acquiring a valve displacement
signal which is measured by the laser displacement sensor in operation of the engine; and S3, comparing the valve displacement
signal which is measured by the laser displacement sensor with a preset valve displacement
signal, thereby determining whether the
engine valve mechanism motion characteristic is abnormal. The invention further provides an engine valve mechanism motion characteristic test
system. According to the engine valve mechanism motion characteristic test method, the laser displacement sensor in the engine cylinder is directly used for measuring the valve of the engine valve mechanism. The engine valve mechanism motion characteristic test method has advantages of: high versatility, convenient use and higher accuracy.