带电质点(或带电粒子)在匀强磁场中运动,在某些条件下质点的运动方式及其运动轨迹都比较复杂.物理学中对复杂运动的研究大都使用分解运动的方法.其目的是:把一个复杂的运动拆分成两个或多个简单的运动。好处是:能够化模糊为清晰、化抽象为直观、化繁琐为简捷.本文用此法分析两个实例. Charged particles (or charged particles) move in a uniform magnetic field. Under certain conditions, the motion of the particle and its trajectory are relatively complex. The study of complex motion in physics uses a method of decomposition motion. Its purpose is to: Divide a complex movement into two or more simple movements. The advantages are: to be able to use ambiguity for clarity, abstractness for visualization, and complexity for simplicity. This article uses this method to analyze two instances.