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Under the physical mixed doping of different amounts of SiO₂, high temperature <i>in-situ</i> XRD, TEM, XPS and Rietveld full spectrum fitting were used to analyze the change rule of chemical bond and the influence of silicon on the transformation mechanism of anatase to rutile (A→R) TiO₂.The results show that the influence mechanism is controlled by distortion energy and crystal nucleus formation. When the doping amount of SiO₂ is less than 7.5% (mass fraction, the same as below), the phase transition is inhibited. At this point, Si⁴⁺ replaces Ti⁴⁺ ions in the titanium dioxide lattice, resulting in distortion and inhibiting the A→R transformation of titanium dioxide. When the doping amount of SiO₂ is greater than 7.5%, it is the promotion effect. At this time, the excess SiO₂ acts as the crystal nucleus of rutile, thus promoting the transformation of A→R.