The present invention relates to a gasification burner comprising a main burner, N-stage sub-burners arranged on the inner side of the main burner, where N is an integer greater than or equal to 1, the main burner and each stage of the sub-burners have independent fuel channels and oxidant channels respectively, the main burner and each stage of the sub-burners are arranged in a coaxial sleeves from outside to inside; the inner diameter of the main burner is larger than the outer diameter of the first stage of the sub-burners, and the inner diameter of each stage of the sub-burners is larger than the outer diameter of its next stage of the sub-burners; the gasification burner can ensure fuels and oxidants to be mixed fully and evenly in limited reaction space and residence time, accelerate combustion reaction rate, thereby improving fuel conversion rate and gasification performance; meanwhile, it can flexibly adjust flame shape without reducing the load of gasifier furnace by adjusting the load of the main burner and each stage of the sub-burners, thereby effectively avoiding overheating of the gasifier furnace to meet different production load requirements of project sites.