The invention relates to a mixing device of latex and expandable resin microspheres. The device comprises a peristaltic pump, a hose, a mixing nozzle, a microsphere chamber, a mixing stirrer, a screw pump, and a latex chamber. The mixing nozzle is mainly composed of an upper connection flange, a latex injection pressure chamber, a latex injection pipe, a micro-powder delivery pipe, a flow-guide cover, and a lower connection flange. According to the invention, latex is added into the latex chamber; with the screw pump as a dynamic and metering device, the latex is delivered into the mixing nozzle; through the latex injection pressure chamber, the latex is delivered to the latex injection pipe, and enters the mixing stirrer; the resin microspheres are sucked from a resin microsphere bag through the microsphere chamber; with the peristaltic pump as a dynamic and metering device, the microspheres are delivered into the mixing nozzle through the hose; with the micro-powder delivery pipe and the flow-guide cover, the expandable resin microspheres are delivered to the middle of the latex at the latex injection pipe, and enters the mixing stirrer with the latex; and with the mixing stirrer, the latex and the expendable resin microspheres are uniformly mixed, such that explosive explosion performance and product quality are improved. The device provided by the invention has the advantages of simple structure and smooth material flow. The expendable resin microspheres are delivered in the device, such that dust is substantially prevented. Metering is carried out by using the peristaltic pump, the screw pump, and the mixing stirrer, such that the two materials can be outputted with any ratio, and material uniform mixing can be realized.