Abstract: In order to ensure the safe and economic operation of the four-stage gathering and transportation system of "transfer station–united station–united station–initial station", a gathering and transportation system in Shengli Oilfield was selected as the research object, and the optimization model for the overall operation parameters of the gathering and transportation system based on the treatment effect of the united station was established under the condition of a fixed process flow and considering hydraulic and thermal constraints. Random test method was used to solve the model. The results show that on the premise of satisfying the requirement of water content in crude oil and the oil content in waste water, the cost is saved by 1 771 yuan/d, the energy consumption cost is reduced by 8.3% and the efficiency of the gathering and transportation system is improved by 4%, demonstrating the remarkable optimization result. The research results can provide theoretical guidance for actual production and operation, further realizing energy saving during production.