New technology,new product,new material,new process are widely used in the power supply system of Yangshan deepwater port phase IV project.For example,the over-voltage protector with dual safety protection device for all phases in six posts guarantees more reliable and safe operation of the equipment；the use of DEHN series earth clamp not only facilitates the construction,but also ensures easy control of construction quality；the roxtec cross sealing system effectively solves the problem of cable sealing and future expansion.