To improve performance of distribute Hash table (DHT) networks under churn, we study an adaptive mechanism of the routing table for Kademlia protocol. Based on a quantitative analysis, we propose an algorithm for the K value to adjust the routing table size to adapt to the churn rate. The churn rate is estimated from the available data in the routing table. Simulations show that the proposed algorithm can significantly reduce lookup latency under churn and raise the network’s crash point by nearly 10%. Even when the churn rate fluctuates severely, the network still has a satisfactory performance.