Abstract: In the ultra-high-voltage and long-distance DC transmission system using the half-bridge modular multilevel converter（MMC） with high-/low-voltage valve connection, the ultra-high-voltage DC circuit breakers required for fault clearance are immature and costly. Aiming at the above problems, this paper proposes an embedded MMC topology with high-/low-voltage valve connection. According to the basic principle of full-bridge sub-module operation, an external embedded bridge arm and an internal embedded energy transfer branch are designed to reverse the voltage polarity of the MMC with the high-voltage valve. The converter station of the half-bridge MMC can realize the non-blocking DC fault ride-through with a lower cost than that of the hybrid MMC. Based on the switching sequence of each branch and the switching time of different devices during fault clearing, the fault ride-through control strategy is designed. By analyzing the current and voltage stress of the device in each stage, the basis for device selection and number configuration is given. Finally, the effectiveness of the proposed control strategy is verified by PSCAD/EMTDC simulations. The device cost and operation loss of the proposed strategy are compared with the existing MMC schemes, which shows the proposed strategy is more economical.