Abstract: With the rapid increase in the integration of renewable energy resources and the transition of the power system from a synchronous system to a multi-area asynchronous interconnected system, the system is gradually exhibiting the characteristic of "low inertia and lack of frequency resources, " which highlights the issue of frequency stability. Leveraging the fast power control capability of a high voltage direct current transmission system (HVDC) can achieve frequency control in asynchronous interconnected systems and facilitate the sharing of primary frequency reverses, enhancing the frequency stability and security of the asynchronous interconnected system. This paper provides an overview of domestic and international frequency control methods for HVDC systems and research on frequency stability analysis for asynchronous interconnected systems. The basic principles of frequency control methods for two types of HVDC, i.e., line commutated converter (LCC) and voltage source converter (VSC), and the frequency stability analysis method for asynchronous interconnected systems, are introduced in detail. Finally, an overview of the current issues and future research directions concerning frequency stability analysis in multi-area asynchronous interconnected systems and HVDC frequency control is provided.