A single-walled carbon nanotube flexible transparent conductive thin film with a carbon welded structure and a preparation method therefor. In the process of growing a single-walled carbon nanotube by means of floating catalyst chemical vapor deposition, the concentrations of a catalyst and a carbon source and the residence time thereof in the constant temperature region are reduced, so that part of the carbon source decomposed by means of the catalyst forms an sp2 carbon island which is welded at the intersection of individual single - walled carbon nanotubes, and finally, a single-walled carbon nanotube thin film with an sp2 carbon island welded structure is formed. The thin film of the structure has better photoelectric properties, chemical stability and flexibility than the ITO thin film on a flexible substrate. The contact resistance between carbon nanotubes is reduced, the formation of tube bundles and a large absorption of light are inhibited, and a high-performance flexible transparent conductive thin film is obtained by designing and preparing the individual carbon nanotubes bonded by means of a carbon welded structure. The high-performance flexible transparent conductive thin film is of great significance for promoting the application of a carbon nanotube thin film in the field of high-performance optoelectronic devices.