异型变径管近年来得到广泛应用，但管道复杂的应力分布也为设计和施工带来诸多难题。实际使用中常出现管道开裂现象，造成停水停电等诸多不利影响,所以设计和施工前有必要进行计算机仿真分析。利用FLUET有限元分析软件对异型变径管进行模拟，研究了在常流和非定常流情况下管道内部流体速度和压强的分布情况。模拟结果表明，定常流变径管中部流体速度最大，压强最小；非定常流在入口变径过渡段1/3处，压强最大；在入口段，压强是先小后大再小，出口处是先大后小再大。

shaped tube has been widely used recently，but complex stress distribution in the pipeline has bought a lot of problems for design and construction。It often occurs the pipe cracking in the practicle, which causes many negative effects such as water and electricity discountinued.so it is necessary to carry out computer simulation analysis before design and construction. It has been simulation analysised with the finite element analysis software fluent。It had studied pipeline internal fluid velocity and pressure distribution of shaped pipe in the case of steady flow and unsteady flow。The simulation results show that fluid velocity of steady flow show maximum value in the middle of variable diameter pipe and pressure minimum, and for unsteady flow in the entrance, pressure maximumin the transition segment one-third.in the entrance section pressure is the first small to big and small，but it is big then small big in the exit。