The invention relates to an electromagnetic detecting device in the field of optical technology measurement, and provides a surface nano-structure magnetic measuring device. The surface nano-structuremagnetic measuring device comprises a laser device, a delayer, a 1/4 wave plate, a concave lens, a convex lens I, a plane mirror, a polaroid, a beam splitter, a convex lens II, a lens table, an atomic force microscope I, a probe I, a lens seat, an objective lens, a sample, a Hall plate, a sample table, a signal generator, an oscilloscope, a detector, a magnet, a pre-amplifier, a differential amplifier, a compensator, an analog-digital converter, a computer, an atomic force microscope II and a probe II, the probe I and the probe II are atomic force microscope probes with the same overall dimension, the appearances of the probe I and the probe II are circular truncated cones, the probe I is provided with a through hole in the axis direction of the circular truncated cone, a wedge-shaped block is cut off on one side of a diagonal axis through a point, which is the closest to the forward direction of an x axis, on the periphery of the bottom surface of the circular truncated cone of the probe I, an oblique plane is formed on the bottom surface of the probe I, a five-degree angle is formed between the oblique plane and the horizontal plane, and a magnetic is formed by connecting four secondary magnets which are the same.