Generally speaking, we will check in advance when the mixer is in use, but because the soil residue is not too noticeable inside the mixer, as long as we look at it slightly, we can find this situation. So we can check this problem before using it. This situation is preventive. If this happens, we must first prepare the emergency drive hose, turn off the mixer, remove the high-pressure oil pipe joint on the hydraulic motor, and then turn off the rescue vehicle to remove the high-pressure oil from the hydraulic motor. The corresponding joints are connected by an emergency drive hose. In the position where the handle of the legal aid rescue vehicle needs to be pulled out of the discharge, the concrete in the vehicle will be discharged. After we have finished all of this, we must remove the drive hose to restore the original condition of the two cars. We can also put a wooden wedge between the roller and the raceway to control the rotation of the mixing drum. We must pay attention to safety. Turn off the engine, remove a high-pressure oil pipe of the hydraulic motor, and the mixing drum can rotate freely to control the mixing. Rotate the barrel to turn the service hole to the lower part, then open the service hole to clear the concrete inside the barrel. At this time, we must pay attention to safety. After the concrete is discharged, restore the original state of the mixer.