wherein the glow discharge sputtering unit comprises a cavity, a cathode plate, a magnet, a sealing ring, an insulating plate, an anode tube, and a ceramic tube;

a sample is in airtight contact with the cathode plate of the glow discharge sputtering unit as a cathode, and the cavity forms a closed discharge space;

the magnet is annular and arranged outside the anode tube through the ceramic tube, and the magnet is located and embraced between the insulating plate and the cathode plate;

a positive electrode and a negative electrode of the glow discharge power supply are electrically connected to the cavity of the glow discharge sputtering unit and the sample, respectively;

the gas circuit automatic control unit is connected to the cavity of the glow discharge sputtering unit via a gas pipeline, and evacuates the cavity and introduces an inert discharge gas at a certain flow rate;

the spectrometer is connected to the glow discharge sputtering unit through a light guide device, and collects a spectral signal generated during a glow discharge sputtering of the sample in real time, and monitors elements signal condition in a depth direction of the sample sputtering, so that precise preparation of different layer microstructures is realized;

the computer is respectively connected to the glow discharge power supply, the gas circuit automatic control unit and the spectrometer, and is used for setting discharge parameters of glow discharge sputtering, collecting and displaying the discharge parameters during glow discharge sputtering and a gas pressure value in the cavity of the glow discharge sputtering unit in real time, and processing and displaying the spectral signal generated during the glow discharge sputtering of the sample and collected by the spectrometer in real time;

a central axis of the magnet coincides with a central axis of the anode tube; the direction of a magnetic force line of the magnet is perpendicular to a surface of the sample; and after a magnetic field and an electric field are applied, charged particles perform a spiral movement as follows: the charged particles make a circular motion perpendicular to the magnetic field, and move toward the surface of the sample under the action of the electric field;

a fluid simulation module; wherein the fluid simulation module simulates a distribution of the gas pressure in the cavity of the glow discharge sputtering unit; a gas inlet position, a gas inlet angle and a gas flow rate of the cavity are optimized according to a simulation result, so that a non-uniformity of a distribution of the electric field in the glow discharge sputtering unit is counteracted, and a flat preparation of the sample surface is realized, wherein the sample is in mm or cm scale.