An immersion cooling system includes a cooling tank and a filtration system. The cooling tank is configured to accommodate a liquid coolant and an electronic device immersed in the liquid coolant. The filtration system includes a pipeline, a pump, a filter and a cooling device. The pipeline is in fluid communication with the cooling tank. The pump is disposed in the pipeline and is configured to drive the liquid coolant to flow through the pipeline. The filter is disposed in the pipeline and is configured to filter the liquid coolant. The cooling device is connected to the pipeline and is configured to cool the liquid coolant. The pipeline has an inlet connected to the cooling tank. The cooling device is located between the pump and the inlet of the pipeline.