Numerous controversies are existed at domestic and abroad up to now about the effect of strong magnetic field treatment on the structure of the aqueous solution. However, few pieces of literature have studied the structure of salt solution with the same treatment. Raman spectroscopy was used in this paper to determine the scattering data of high-purity water and NH₄Cl aqueous solution with mass fractions of 1%, 5%, 10%, 20% and 28% at a different time under the external strengthened magnetic field of 1.8 T. It provided a feasible method for Raman spectroscopy to investigate the effect of strong magnetic fields on the structure of the aqueous solution, enriching the Raman spectroscopy research field. According to the experimental results, the value of stretching vibrations of hydrogen bonds in water molecules gradually increased with the increased magnetization time. It could reach saturation after a certain magnetization time. The saturation time of high-purity water and NH₄Cl aqueous solution with different mass fractions was different. The time of high-purity water and NH₄Cl aqueous solution with mass percentages of 1%, 5%, 10%, 20% and 28% was 150, 120, 120, 100, 80 and 80 min. The time to reach the saturation of magnetic effect showed a decreasing trend with the increased mass fraction of NH₄Cl aqueous solution. The demagnetization memory time of high-purity water and different mass fractions of NH₄Cl aqueous solution was measured after the magnetic field was removed. The demagnetization memory time of high-purity water and NH₄Cl aqueous solutions with mass fractions of 1%, 5%, 10%, 20%, and 28% was 30, 40, 50, 60, 80 and 80 min, respectively. The demagnetization memory time presents an increasing trend with the increased mass fraction of NH₄Cl aqueous solution. NH₄Cl aqueous solutions with different mass fractions after 2 h of magnetization was processed by deconvolution fitting. According to the deconvolution fitting result, NH₄Cl aqueous solution with the mass fraction of 20% increased a peak of N—H compared to NH₄Cl aqueous solution with the mass fraction of 10%. The signal peak gradually increased with the increased mass fraction of NH₄Cl aqueous solution. The structure of the hydrogen bond of DDAA-type decreased with the increased magnetization time, which had a destructive effect on the tetrahedral structure of water. The hydrogen bond of DDAA-type did not change any more when it reached the saturation magnetization time. The influence of 1.8 T magnetic field on the structure of NH₄Cl aqueous solution could be obtained through Raman spectroscopy, which provided a certain theoretical basis for the study of another inorganic salt aqueous solution under the condition of external strengthening magnetic field.