The invention relates to a magnetostrictive displacement sensing flowmeter. The magnetostrictive displacement sensing flowmeter comprises a sensor electronic bin, a transitional joint, a groove cover, an overflow groove, a metering barrel, a valve block, a damping washer, a straight joint, a measuring wave guide tube and a magnetic ring buoy. The magnetic ring buoy is driven to move in the up-down direction by change of the liquid level of leakage oil, a magnetostrictive effect of a magnetostriction material is achieved, the measuring wave guide tube deforms elastically so that a mechanical wave which is expanded towards two sides is generated, the mechanical wave is received by the sensor electronic bin which is connected with the upper end of the measuring wave guide tube and is converted into an electric signal, and the volume flow of the leakage oil is calculated by comparison and conversion. Owing to the magnetostrictive effect, the magnetostriction property of the magnetostrictive displacement sensing flowmeter is not changed along with time. The magnetostrictive displacement sensing flowmeter has the advantages of high stability, high reliability, high response speed, high resolution precision, non-contact measurement, zero abrasion, long service life and the like. Moreover, the magnetostrictive displacement sensing flowmeter is particularly suitable for measuring micro flow.