The invention relates to a mixer for mixing rubber and plastic particles, which comprises a mixing roller device and a transmission device which are matched with each other. Both the mixing roller device and the transmission device are arranged on a weighing device which is arranged on a support base. The weighing device, the mixing roller device and the transmission device are respectively connected with a control system which is arranged on one side of the support base through circuits. The mixing roller device is driven by a driving wheel through a rolling ring to rotate. The roller has positive rotation and reverse rotation. During positive rotation, an inner spiral pushing auger drives material particles in the roller to lift, rotate, roll and move tangentially and axially along the roller to uniformly mix the materials. Meanwhile, the materials move to the side of a discharge outlet axially under the action of a spiral thrusting force, and the materials are discharged from the discharge outlet through a material lifting plate finally. The mixer for mixing the rubber and plastic particles has the characteristics of high production efficiency, excellent mixing effect, high discharge speed, adjustable speed, accurate discharge, capacity of preventing the material particles from re-bonding, full-automatic control, full closeness, no dust or noise pollution, and the like.