The invention discloses phosphorus-containing methyl vinyl flame-retardant silicone rubber crude rubber, a preparation method therefor and an application thereof. The material has a following structural unit: FORMULA as shown in the specification, wherein X is 2-4, y is 3-6, z is 300-325 and Mw is equal to 18900-27600. The invention further discloses the preparation method for the phosphorus-containing methyl vinyl flame-retardant silicone rubber crude rubber; linear methyl vinyl phosphorus-containing silicone rubber crude rubber with a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide structure in a side chain is obtained; compared with conventional addition methyl vinyl flame-retardant silicone rubber, the phosphorus-containing methyl vinyl flame-retardant silicone rubber crude rubber disclosed by the invention has better flame resistance; and problems of high filling volume and low flame resistance efficiency in a conventional flame-retardant rubber blending process are overcome; and physical characteristics such as good tensile strength, good impact strength and the like of the silicone rubber are kept.