The invention discloses a method for simulating the flow safety assurance of an oil-gas-water mixture transportation pipeline with high height difference. The method comprises the following steps (1), (2), (3), (4) and/or (5): (1) determining whether to fill a hydrate inhibitor or not according to the temperature condition of the interior of the oil-gas-water mixture transportation pipeline with high height difference; (2) controlling the time that an oil phase, a water phase and the hydrate inhibitor do not flow out from the outlet of the oil-gas-water mixture transportation pipeline according to the process that balance is established between the oil phase and the water phase in the oil-gas-water mixture transportation pipeline during production working condition initial stage; (3) determining the influence of situation changes on the outlet parameters of the mixture transportation pipeline according to the situation changes of throughput and delivery pressure in the oil-gas-water mixture transportation pipeline with high height difference during the oil field production period; (4) transporting supplementary throughput in a circulating manner by use of a platform circulating device under a low-throughput working condition; (5) controlling and regulating a circulating pipeline cleaning path and a circulating pipeline cleaning mode. The method can be used for reducing the influence of the dynamic changes of the oil-gas-water mixture transportation pipeline with high height difference on downstream equipment facilities, optimizing the downstream equipment scale of the pipeline and reducing the investment.