The invention discloses a wire tension controller of a multi-strand spring digital control lathe, comprising a shell, a tension control assembly and a tension collection assembly. The tension control assembly comprises a magnetic powder brake and a damping part; the tension collection assembly comprises a cutting fiber wheel and a pressure sensor; the signal output end of the pressure sensor and the magnetic powder brake are respectively connected with an automatic control system of the lathe; and wires are led out from a wire box arranged in the shell to wind a circular cutting fiber groove before being led out of the shell by the cutting fiber wheel. The wire tension controller of the multi-strand spring digital control lathe automatically controls the tension of the wires in the production process, monitors and controls the tension of each strand of wires in a multi-strand spring processing process by the tension collection assembly and a data acquisition and control system, realizes the constant tension of each strand of wires and the uniform and constant tension among various strands of wires, monitors the tension in real time by an application program of an upper computer and fully realizes a self-tuning system of the tension so as to ensure the quality of a finished product of a multi-strand spring.