Introducing the role of Coulomb's law and Ampere's law in the electrical system of units. According to the principle of equivalence between mechanical power and electric power, the current unit ampere（A） is selected as the basic physical unit. The practical unit system and electrical physical measurement standards are introduced. The principles of three quantum standards of electrical measurements and the ways for tracing to the natural constant are described. The role of vacuum permeability in the formulation of the Ampere's law is analyzed. The problem of the compatibility of an electrical quantum triangle with Ohm's law is explored. It is pointed out that the elementary charge constant is not simply derived from the Josephson constant K_J?90 and the Von Klitzing constant R_H?90, but is calculated from the fine structure constant formula. The principle of conservation of energy is the first principle in the system of units, and it is the link between mechanical and electrical measurement units. It is proposed that the displacement current between quantum dots has some influence on the single electron tunneling pump, the vacuum permeability is no longer an ideal constant, and the change of vacuum permeability will be the focus of later theoretical research.