The invention discloses a sending end fault ride-through control method and device for an LCC-MMC power transmission system. The sending end fault ride-through control method for the LCC-MMC power transmission system comprises the following steps that: when it is determined that an alternating-current fault occurs at the sending end of the power transmission system, a receiving end MMC generates afault ride-through control strategy according to the degree of the alternating-current fault, wherein the fault ride-through control strategy involves adding at least one control link, and the receiving end MMC has been configured with a constant voltage control link of which the input contains a direct-current voltage reference value U<*>dc; and the receiving end MMC executes the constant voltage control link and the at least one added control link, so that a direct-current voltage is reduced along with the direct-current voltage of an LCC sending end. With the sending end fault ride-throughcontrol method adopted, the ride-through capability of the power transmission system under the different degrees of faults of an sending end alternating-current side can be realized.