Abstract: To achieve the carbon peak and neutralization, the voltage source converter (VSC) based DC segmented system is an effective way to solve such problems as high renewable energy consuming, short circuit current standard exceeding, and power flow controlling of the urban power load centers. However, with the increasing application of the VSC and the other power electronics devices, the power grid gradually presents the characteristics of low inertia and weak damping, which have had a negative impact on the frequency stability. Therefore, a novel frequency support strategy is proposed for the VSC based back-to-back (VSC-BTB) DC segmented system with large capacity renewable energy integration. Based on the droop control and setpoints adjustment, the equivalent inertia and damping of both the interconnected AC systems are enhanced. The coordinated power exchange and frequency support between the segmented areas are achieved. Moreover, the control parameters are designed by improving the frequency nadir so as to reducing the risks of low-frequency load shedding. The decoupled control of power and DC voltage through the VSCs impels the renewable energy station to participate in the adaptive frequency regulation to mitigate the system frequency deviation. Finally, simulation conducted in PSCAD/EMTDC validates the effectiveness of the proposed strategy.