采用毕奥-萨伐尔定律，应用矢量叠加原理，具体讨论了长度为L= 200 mm 的螺线管的磁场分布.首先推导了单个圆

形载流线圈的磁场在空间分布的积分公式，然后，利用Python 软件求解绘制出了磁感应线，与经典物理教材进行了对比，验证

了理论公式和数值计算的正确性.基于单个圆形载流线圈的结果，得到了有限长载流螺线管磁场全空间分布的理论公式，绘制

了相应的磁感应线分布图，详细讨论了线圈匝数密度、螺线管长度对磁场空间分布均匀性的影响.发现匝数密度大于1000 m-1

时，螺线管在-74 mm ≤ z ≤ 74 mm 范围内的磁场可视为均匀磁场.本文的结果为大学物理和大学物理实验教学提供了可靠、

直观清晰的素材.

The magnetic field of solenoid with length L = 200 mm is discussed in detailby using the Biot-Savart

law and the principle of vector superposition.The magnetic fieldof a single current-carrying circular coil is exactly

derived. Pythonis adopted to integrate the analytical expressions and visualize the corresponding magnetic induction

line. Compared to the classical physics textbooks，both the theoretical derivations and the numerical solutionsare

verifiedvalidly. Then the same analysis are carried out on both the magneticfield and the visualization of magnetic

induction line of a finite current-carrying solenoid. The influence of coildensity and solenoid length on the uniformity

of magnetic field are discussed in detail. It is found that the magnetic field is regarded as uniformity in the range

of -74 mm ≤ z ≤ 74 mm of a solenoid when the density is greater than 1000 m-1 . The results in this paper provide

intuitive and clear teaching materials for theoretical and experimental teaching in College Physics.