The invention relates to a new technology for conducting grouting filling for underground coal goaf and abandoned workings. The technology is characterized in that in grouting construction, the methods of sequentially conducting pressure-free grouting, micropressure grouting and repeated pressure grouting (increasing grouting pressure gradually) are adopted; the grouting filling construction efficiency can be greatly improved for the underground coal goaf and the abandoned workings, the construction period is greatly shortened, the construction cost is lowered, and then the pressure of grouting is truly increased to be about 5 MPa, and the construction quality is guaranteed.