Abstract: The lamp-pumped rubidium atomic clock has a wide range of applications in satellite navigation and positioning system.It has many advantages,such as long life,very low random frequency drift noise,good short and mediumterm stability and other significant advantages,but its accuracy and long-term stability are low.With the development of navigation and positioning system,the traditional rubidium atomic clock can not meet the new generation of navigation and positioning system.The microwave atomic clock of Hg⁺ion in ion trap has realized the performance index of hydrogen atomic clock.Compared with the traditional rubidium atomic clock,Hg⁺clock has great application prospects.There are many similarities and differences between rubidium atomic clock and Hg⁺atomic clock.The analysis of the differences between them can draw lessons from the existing rubidium clocks and deepen the understanding of the working process of Hg⁺clock.The principle and key technology of the two are compared and analyzed,which can be used for reference for the development of Hg⁺clock.