The invention discloses a mechanized upward-slicing wedging mixed filling mining method. When mining is conducted through the upward horizontal slicing filling process, upward stoping and filling are conducted with each slice being 3-4 m, and slices from bottom to top are alternately subjected to full tail sand cementing filling and waste stone wedging mixed filling. During wedging mixed filling, waste stone is stacked upward to form a quadrangular frustum pyramid. The laying range of the bottom waste stone is arranged according to the size of a stope, and certain spacing is kept with an adjacent stope. Tail sand cementing filling is still conducted on the two sides of a waste stone pile, and making contact with upper and lower layered tail sand cementing filling bodies is conducted, the whole strength of a mixed filling body is guaranteed, and dilution caused by caving of an ore body or surrounding rock at the time of being unstable is stopped. When the upward horizontal slicing filling process is adopted, the strength of the filling body can be guaranteed, and a large quantity of the downhole waste stone can be consumed, so that the waste stone is not out of a pit, and accordingly the cementing filling material is saved, and the filling cost is reduced effectively.