The invention relates to a 
nitrogen-
doped carbon supported 
tin and 
tin oxide nano 
composite material as well as preparation and application thereof. A preparation method of the 
composite material specifically comprises the following steps: (1) weighing SnCl2 and NH4F, dissolving the components into water, further pouring the solution into a reaction container, vertically putting pretreated carboncloth into the container of the reaction container, performing a 
hydrothermal reaction, performing cooling, taking out the carbon cloth, performing cleaning, and performing 
drying; (2) weighing 
dopamine, dissolving the 
dopamine in a 
Tris buffer, further vertically suspending the prepared carbon cloth loaded with a Sn2O3 nano 
chip array material, performing a standing reaction, taking out the carbon cloth material, performing cleaning, and performing 
drying; and (3) performing calcining treatment on the carbon cloth which is prepared in the step (2) and has the polydopamine wrapped Sn2O3 nano 
chip array material, so as to obtain a target product, namely a Sn / SnO2@C nano 
composite material. Compared with the prior art, the 
nitrogen-
doped carbon material into which a 
metal nano particle composite carbon material is introduced is applied to electrocatalytic 
carbon dioxide reduction, and provides a novel idea for preparation of 
carbon dioxide electrocatalytic reduction catalysts.