Supported SCR denitration catalyst of medium and low temperature flue gas and preparation method and application thereof

The invention discloses a supported SCR denitration catalyst of medium and low temperature flue gas and a preparation method and application thereof. The catalyst comprises the following components: vanadium element, transition metal M and carrier. The addition of the vanadium element is 0.5-4wt% of the total mass of the catalyst by weight percent via calculating the amount of V2O5; the addition of the transition metal M is 1-14wt% of the total mass of the catalyst by weight percent via calculating the total amount of oxide; and the addition of the carrier is 80-98.5wt% of the total mass of the catalyst by weight percent. Compared with the widely used commercial catalyst, the catalyst of the invention reduces the cost by more than 30%, broadens the medium and low temperature ranges of SCR catalyst activity, and has the characteristics of simple preparation, low cost, high activity, strong sulfur poisoning resistance and the like.