This letter presents 25 supova candidates discovered from SDSS-DR7 by using our dedicated method, called Sample Decrease. Ten of them have been confirmed by other research groups, while the remaining 15, including 14 Type Ia and one Type Ⅱ, are first discovered based on Supova Identification analysis. The results demonstrate that our method is reliable. The description of the method and some detailed spectral analysis procedures are also presented.