Calcium carbonate is an important inorganic filler in rubber production, with capacity building and reinforcement functions.With the growing demand for rubber in China, calcium carbonate usage is expanding, and its production costs and energy consumption are becoming increasingly problematic.Steel slag is a byproduct of the steelmaking process and has problems such as low utilization and large accumulation.The main components of steel slag are CaO, SiO2, FexOy, Al2O3, etc. The physical and chemical properties of steel slag are similar to those of traditional fillers, and the wear resistance and porosity of steel slag are excellent, so the use of steel slag to replace some calcium carbonate as a rubber filling material not only has important research significance but also can alleviate the problems of energy consumption and environmental pollution. Based on this, this study used the combined treatment of steel slag with homemade functional compound and ultra-fine vertical mill to obtain a sample shield powder with a particle size of 800 and prepared shield powder/rubber bulking composites with different dosage ratios of active calcium carbonate to shield powder.The prepared shield powder/rubber bulking composites were tested for their properties using an intelligent volcano meter, an electronic tensiometer, a rubber hardness tester and a microcalorimeter (MCC), and the shield powder/rubber bulking composites were characterized and analyzed by thermogravimetric analysis-Fourier transform infrared spectrometer (TG-FTIR) and Raman spectrometer (Ram).The results show that replacing part of active calcium carbonate by shield powder has a certain promotion effect on the vulcanization performance of the rubber system and can improve the vulcanization speed of shield powder/rubber capacitated composites.The addition of shield powder can improve the compound rubber systems mechanical and flame retardant properties. Analysis of the shield powder/rubber bulking composites by microcalorimetry and Raman spectroscopy revealed that the heat release capacity and total heat release of the rubber system after the replacement of part of active calcium carbonate by shield powder decreased, and the graphitization of carbon residue increased, further indicating that the replacement of part of active calcium carbonate by shield powder also has certain flame retardant properties while ensuring the physical properties of the shield powder/rubber bulking composites. Thermogravimetric-infrared analysis shows that the gas produced during the cracking of the shield powder/rubber capacitated composite is mainly hydrocarbons. Adding a home-made functional compound can alleviate the incompatibility of the steel slag interface with the rubber interface and optimise the rubber composite.The above study provides data and theoretical support for preparing shield powder/rubber bulking composites with better performance.