The invention discloses a novel NAMPT and IDO dual inhibitor, and a preparation method and medical applications thereof, and more specifically relates to a furazan compound, or pharmaceutically acceptable salts, solvates, prodrugs, esters, racemic compounds, and isomers of the furazan compound, and pharmaceutical compositions containing the furazan compound, and applications of the furazan compound or the pharmaceutical compositions in the field of anti-tumor drug preparation. According to the preparation method, reasonable combination of active segments of an IDO inhibitor and a NAMPT inhibitor is adopted so as to obtain the furazan kind IDO / NAMPT double target inhibitor. On one hand, the furazan kind IDO / NAMPT double target inhibitor is capable of realizing dual inhibition of NAD<+> biosynthesis, and possesses higher anti-tumor inhibition activity, and one the other hand, inhibition of IDO activity is capable of promoting T cell propagation effectively, so that the impurity of bodies on tumor cell attacks is improved. The furazan kind IDO / NAMPT double target inhibitor or the pharmaceutical compositions of the furazan kind IDO / NAMPT double target inhibitor are promising in application prospect, and are promising to be developed into anti-tumor drugs.