The invention relates to a device for measuring internal stress of ferromagnetic material by pulse electromagnetic field. It is composed of detector, pulse electromagnetic field circuit and data acquisition and processing device, the detector part is composed of drive coil (7), heel piece (9) with one fieldpole and two measure poles and two groups of induction coil (8, 8'), weighing cell (4) is placed above the detector (5), the detector (5) is placed above the tested workpiece (6), which are clamped by jig; the pulse electromagnetic field circuit provides 1-3 Tesla strong incentive pulsed electromagnetic field for drive coil (7), the current signal in drive coil (7), the voltage signals of the two groups of drive coils (8, 8') are processed by data acquisition and processing device, thenthe magnetization curve and magnetic hysteresis loop of the tested workpiece (6) are obtained, after various kinds of magnetic parameters of the tested workpiece are determined, the rating curve between the internal stress and various kinds of magnetic parameters are established.