The invention discloses a preparation method and application of a bioactive glass to orthopedics and dentistry, and belongs to the field of pharmacy. The bioactive glass is prepared through the following steps: mixing concentrated nitric acid and ethanol to obtain a mixed solution I, adding ethyl tetraethyl into the solution I, pre-hydrolyzing to obtain a solution II, adding phosphorus pentoxide into the solution II, stirring to obtain a solution III, adding calcium nitrate terahydrate in the solution III, and fully stirring and dissolving to form a clear gel; then placing the clear gel in an oven at 60 DEG C to form gel, and then drying at 130 DEG C for 72 h; and finally, conducting ball milling, sieving and calcining under the temperature of 700 DEG C to obtain the bioactive glass. The invention has the advantages that the obtained bioactive glass can be subjected to repeated heat treatment without crystallization and can be shaped into different shapes, and is applicable to plastic surgery operations, such as bone graft, bone defect filling and oral rehabilitation; and the invention has the advantages of simple equipment, low price of raw materials, and possibility of mass production.