The manifolds are flow distribution devices commonly used among the heating furnaces,heat exchangers,reactors,boilers,and so on.The fluid flow distribution uniformity in the manifolds,to a large extent,decides the operation safety and economy of these devices.The fluid flow characteristics in T-type pipes and manifolds were systematically researched and analyzed by the Fluent simulation software in this paper,exploring the influencing factors such as the inlet mass flow rate on flow distribution non-uniformity,and providing some measures to improve the flow distribution uniformity.The simulation results have certain guiding significance for the optimization design of manifolds and their safe economic operation.