Power Blender Method is a reliable and quality improvement method for shallow and middle ground by utilizing the power blender (a soil improvement machine equipped with trencher-type agitating mixer onto the base machine) to agitate and mix improved soil and improved materials continuously and vertically for equal and fine solidification. Three types of power blender method are: The slurry injection type that improvement materials such as cement or stabilizer is mixed in a slurry state and injected into the ground to mix in-situ soil and improvement material by force; The surface spray type that improvement material is spread on the surface and mixed by the power blender; The surface spray with precipitator type that improvement material pumped from a lorry is spread on the surface while collection and measurement are done simultaneously by a spreading machine with a precipitator, then agitation and mixing are done by the power blender.