Abstract: The annual throughout is often not equal to the designed annual throughout, it changes randomly in actual operation, optimal square approximation is used to identify the pipeline's designed throughout. Based on it, the authors establishe the optimal designed two level hierarhical model of hot oil pipeline including annual throughout model and optimal parameter model. Combining PSO (Particle Swarm Optimization) and MDRP ( Mixed Discrete Random Programming ) forms the comprehensive PSO MDRP, which can be applied to actualize the whole optimization design of hot oil pipeline. The calculation examples show that PSOMDRP can save more annual expense compared with PSO, MDRP and MDCP (Mixed Discrete Complex Programming)for the same design. It also shows using PSOMDRP improves the design quality.

Key words: oil pipeline, throughout, mathematic model, PSO, optimal design