钻井过程中，全井钻头类型的优化是一个多阶段决策问题。本文根据系统工程理论，生成全井钻头序列优化组合多阶段决策树，并构造出全井钻头动态规划的状态转移方程、指标函数、由最小化理论寻求最优树枝途径，以此获得全井钻头序列优化组合及工作参数优选，这是深井、超深井钻井，缩短钻（建）井周期，获得高钻速、低成本的重要途径 During drilling, the optimization of full-bore bit type is a multi-stage decision problem. Based on the theory of system engineering, a multi-stage decision tree of drill bit sequence optimization is generated, and the state transfer equation and index function of the whole drill bit dynamic programming are constructed. The optimal branch is sought by the minimization theory. Optimization of the sequence combination and optimization of working parameters are important ways for deep well and ultra-deep well drilling, shortening the drilling cycle, obtaining high drilling speed and low cost