In recent years, there are more and more researches on electrospinning, but some problems are still difficult to solve, such as the difficulty of controlling the structural size of the product fiber. Therefore, we need to explore basic theories, perform dynamic analysis on the jet behavior, so that the quality of the produced fiber is good and the output is large. In this paper, mechanical analysis of the unstable segment of electrospun charged jet is carried out and the dynamic model of the jet is established. The trajectory of the jet in the unstable segment is calculated using Matlab software. Basing on the Maxwell viscoelastic model, establish a dynamic model of the jet. Taking a single jet in a single-needle electrospinning device as the research object. The jet is discrete into multiple charged particles, and the movement trajectory of the charged particles is simulated using Matlab software. The results show that the influence of voltage on jet trajectory distribution is obvious.