The invention discloses a flexible direct-current transmission low-voltage ride-through control method suitable for occasions without communication between double ends. By predicting terminal dropout voltage and changing power instructions to achieve low-voltage ride-through of a system, it is guaranteed that no overvoltage phenomenon happens to the system during a fault, and meanwhile a certain amount of energy can be provided for a load to achieve uninterruptible power supply; direct-current bus voltage detection and power control are introduced, and by detecting direct-current bus voltage and the variation slope of the direct-current bus voltage, the dropout depth can be judged. Power control is carried out on the basis of dropout depth detection to change the power output of a converter valve system and guarantee the power balance of a double-end system; no communication is conducted between the double ends, and thus the system stability is enhanced.