The invention discloses an NAMPT/HDAC dual-target inhibitor and a preparation method thereof. The dual-target inhibitor is an amide derivative and pharmaceutically acceptable salt thereof, wherein a structure general formula is represented as the formula (I). A pharmacological experiment proves that the derivative or the salt thereof have very strong inhibition activity on the nicotinamide phosphoribosyl transferase and the histone deacetylase, and have high in-vitro anti-tumor activity and excellent in-vivo tumor inhibiting effect. The invention also provides a preparation method of the derivative and the pharmaceutically acceptable salt thereof, and an application in preparation of an NAMPT inhibitor, a HDAC inhibitor, and anti-tumor medicines.