通过力学分析，推导出计算钻压的迭代公式，即建立了计算井底钻压的力学模型．由此式不仅可以确定钻压与大钩负荷之间的关系，还可以确定任一铰链处的受力状况．随着大钩负荷的增加，井底钻压减小，同时，从井底到井口的各铰链处受力逐渐加大． Through mechanical analysis, an iterative formula for calculating weight-on-bit is derived, that is, a mechanical model for calculating the weight on bit of bottom hole is established. This formula can not only determine the relationship between weight-on-bit and hook load, but also to determine the force at any hinge. As the hook load increases, the bottom hole WOB decreases, and at the same time, the forces at the hinges from the bottom to the wellhead gradually increase.