Treatment: the pipe blockage of pump truck is a worldwide problem, and the common cause is caused by non-standard operation. 1) Check the pressure system for insufficient pressure; 2) The proportion of raw materials is not correct, and the proportion of sand, stone and cement is uneven, resulting in unclear pumping and changing the proportion. If the operation is improper, the normal shutdown shall not exceed 2 hours (the specific time shall be adjusted according to the material ratio). If the time exceeds the specified time, it needs to be cleaned.