The invention discloses a hollow-core rock wool and a preparation method and applications thereof, belonging to the field of temperature-preservation and heat-insulation materials. The hollow-core rock wool consists of the following materials by weight percentage: 60-70% of basalt, 20-30% of dolomite, 2-6% of diabase, and 4-8% of fluorite. After being mixed evenly, the materials are put into a cupola and melted at high temperature of 900-1000 DEG C, and then the hollow-core rock wool is obtained. The rock wool has long fiber, good temperature-preservation and heat-insulation properties, fireproofing capability, good elasticity, strong tensile force and good hand-feel, thus being head and shoulders above the slag cotton. All properties are in full compliance with standards of nation, national defense, industry, aerospace, navigation, construction, petroleum, chemical industry, and agriculture. The hollow-core rock wool can be used for the industries such as electric power, chemical industry, petroleum, construction, metallurgy, textile, shipping, automobile, train, airplane, heating pipe and the like, and is the temperature-preservation and heat-insulation material of industrial equipment such as pipeline storage tanks, boiler flues, heat exchangers, large airports, gyms, large-scale cold storage and the like, and civil building engineering.