利用离散递推的计算方法，推导了移动大热区拉锥系统中拉锥光纤形状的计算公式。在推导出的计算方法的基础上，定性地分析了加热火焰移动距离、加热火焰移动速度、光纤拉伸速度等移动大热区拉锥系统的设定参数对拉锥光纤形状的影响，其中主要分析了对拉锥光纤锥腰形状的影响。发现加热火焰移动距离对拉锥光纤锥腰宽度和锥腰半径都有很大影响，而加热火焰移动速度、光纤拉伸速度则对拉锥光纤锥腰半径有很大影响，但是对拉锥光纤锥腰宽度影响不大，这些发现对大热区熔融拉锥技术具有一定的理论指导意义。

The calculation formula for the shape of tapered fibers in movable largezone furnace fibertapering system is derived by the discrete deducing method. We analyze the influences of some setting parameters of the movable largezone furnace fibertapering system, such as moving distance, moving speed of the furnace and moving speed of the holders, on the shape of tapered fibers. The impact to the shape of the fiber waist is discussed primarily. It is found that the furnace moving distance affects the fiber waist length and radius greatly, while the moving speed of the furnace and the holders can effect the fiber waist radius visibly. However, both the speed of the furnace and the holders cannot affect the fiber waist length obviously. All these results are important for the largezone furnace fibertapering technology.