A new crystalline form of Agomelatine, its preparation method and application are provided. There are main peaks where diffraction angles 20 are 11.13, 11.82, 17.49, 18.29, 19.48, 19.72, 20.50, 21.76, 22.54, 22.97, 24.56, 25.36, 27.16 and 31.93 in the X-ray diffraction pattern of the crystalline form powder of Agomelatine. The new crystalline form has good purity, stability and repeatability, and has advantages in pharmaceutics. In addition, the stability and solubility are better than those of current crystalline forms.
