The concrete mixing truck is composed of automobile chassis and special equipment for concrete mixing. The chassis of concrete mixing trucks produced in our country mostly adopts the second general chassis provided by the truck manufacturer. Its special mechanism mainly includes PTO, front and rear support of mixing drum, reducer, hydraulic system, mixing drum, manipulation mechanism, cleaning system and so on. The working principle is that the power of the automobile chassis is taken out by the power taking off device, and then drives the hydraulic pump. The mechanical energy is transformed into the hydraulic energy to transmit the motor. The motor drives the reducer again, and the reducer drives the mixing drum to mix the concrete.