Abstract Multilateral drilling technology has advanced to the point that it is now feasible to explore and extract resources from previously unprofitable reservoirs. It may also help to enhance field development management by allowing for more efficient fluid flow from the formation. Despite its various benefits, a multilateral well has some drawbacks and requires a significant amount of technical work to optimize drilling parameters and depth and well trajectory rise. The most critical issues occur for a fish-bone lateral when the turns are formed for each lateral. The measurements of WOB are complex and may be inaccurate, leading to torque and drag values that are miscalculated or misread. Currently, the soft-string model and the intermittent contact due to drillstring stiffness are used in torque and drag models. But they also have some limitations, such as the neglection of dimensional changes in the string components when assuming clearance of contact and the inability to fully model the irregularity of the actual well path when assuming complete contact throughout the wellbore. The suggested model is unique in its capacity to estimate precisely anticipate drillstring-wellbore contact forces and solve torque and drag parameters from surface to total depth using a conditional alternating use of the assumption that there is continuous contact of the wellbore wall and the drill string while turning to each lateral and clearance between the drill string and wellbore-wall when drilling through straight sections. The model shows how well path design calculation is done for multilateral wells. A non-constant curvature trajectory is built into the model. The unique procedure for calculating torque and drag in multi-lateral wells is explained with several actual field data tests.