Silicone rubber composite insulators (SiR) materials are widely used in electricity and industry, and waste SiR has the potential to be transformed into new natural energy sources. Thermogravimetric analysis was conducted in a nitrogen atmosphere to study the pyrolysis kinetics of SiR heated at rates (β) of 10, 20, 30, 40 °C/min over the temperature range of 50 to 800 °C. The results showed that during the pyrolysis process of SiR, as the heating rate increases, the peak of the thermogravimetric curve shifted towards higher temperatures, with a temperature change of approximately 100 ℃. Meanwhile, the non-isothermal pyrolysis kinetics of SiR were analyzed using three conversion methods: Kissinger (KAS) method, Friedman (FR) method, and Flynn-Wall-Ozawa (FWO) method. The results showed that the difference in activation energy obtained by the three equal conversion methods did not exceed 10 kJ/mol, and the overall trend was very similar. The activation energy range of SiR pyrolysis was between 44.67~59.65 kJ/mol.