Based on the existing research achievement of submarine cables, the research status of submarine cables at home and abroad is summarized. Taking the XLPE insulation submarine cables as example, this paper systematically summarized the research achievements including the state monitoring and integrated online monitoring systems of submarine cables; the calculation and analysis of submarine cables ampacity, temperature field and energy loss; the construction of the theoretical models of submarine cable designs; the mechanics and load analysis; and the studies on electromagnetic performance and laying technology. The causes of existing problems are analyzed, and improvement measures and suggestions are put forward from the aspects of the structure and process designs of submarine cables, the fault monitoring technologies for operation and maintenance, the laying technology, the simplification and optimization of theoretical analysis models of mechanics and load, electromagnetic field performance, ampacity and temperature field.