The invention relates to a method for preparing 6-cyano phenanthridine and derivatives thereof. The method comprises the steps of adding an azido-terminal-substituted olefin compound represented by aformula I shown in the description, a nitrogen source, a catalyst, an oxidant and an organic solvent into a pressure-proof reactor, carrying out a full reaction at the temperature of 30 DEG C to 60 DEG C, and subjecting a reaction solution to separation and purification, thereby obtaining the 6-cyano phenanthridine represented by a formula II shown in the description and the derivatives thereof, wherein the nitrogen source comprises sodium azide, the catalyst comprises copper powder, cuprous bromide, copper sulfate, copper chloride, copper acetate or cuprous oxide, R1 and R2 in the formulae Iand II are separately the same, R1 is H, F or Cl, R2 is H, or H is monosubstituted or polysubstituted by methyl, chlorine, fluorine, phenyl, tert-butyl or methoxy. Compared with the prior art, the method has the advantages that the method is safe and environmentally friendly, no waste gas and waste water is produced, the substrate adaptability is good, all kinds of substituents can be aromatized/cyanated, the reaction conditions are mild, and the reaction steps are simple.