The partially devulcanization of waste tire rubber vulcanizate was carried out with the newly developed mechanochemical pan mill, which can exert fairly strong compressing and shearing force on the milling materials and avoid the agglomeration phenomenon. The experimental results indicate that the particle size is greatly reduced and the surface is fluffier, crosslink density is reduced to one half without large degradation and heavy damage of rubber backbones. The study of mechanical properties of revulcanizate of SBR and waste tire rubber blends at 1:1 ratio indicates that elongation at break increased from 302% to 447.6%. But the properties of tensile strength, modulus and hardness are reduced. The mechanochemical pan milling process is a simple, low cost and environmental-benign process for waste tire rubber devulcanization at ambient temperature without any use of chemicals and can be used at commercial-scale.