The invention discloses self-emulsifying waterborne alkyd resin as well as self-emulsifying waterborne alkyd paint and a preparation method of the self-emulsifying waterborne alkyd paint. The self-emulsifying waterborne alkyd resin has a solid content of 80 plus or minus 1%, and is the self-emulsifying waterborne alkyd resin with a transparent appearance; the self-emulsifying waterborne alkyd paint is prepared by taking the self-emulsifying waterborne alkyd resin as a matrix, and mixing and stirring the self-emulsifying waterborne alkyd resin with a pigment, a drier, a neutralizer, deionized water, a defoaming agent, a substrate wetting agent, a dispersing agent and a thickener; the non-volatile matter content of the self-emulsifying waterborne alkyd paint is 45-55, the hardness is 0.3-0.5, and the VOC content is below 100g / L; the preparation method mainly comprises the following steps: a) preparation of pigment slurry, b) a mixing stage; the self-emulsifying waterborne alkyd paint iscapable of achieving or approaching the performance of solvent-based paint, and mainly used in building enamels, primers of wooden products, anti-corrosive primers, agricultural machinery, construction machinery, trains, trolleybuses, buses and steel strength beam coating systems.