Four types of piles should be regarded as waste piles. Piles with complete piles and large inclination can reduce the bearing capacity, but most of them are inclined in the same direction to avoid the risk of overall instability of the pile foundation. When there is little waste pile, it can be properly replenished. If there are many waste piles or most of them are inclined beyond the acceptance standard, cement mixing piles can be considered as rigid-flexible pile composite foundation. If there are too many waste piles, the pile type will be changed.