An electric line paying-off fixed-length cutting device is used for solving the problem of inconvenience of straightening and cutting of hard lines and comprises a base, a hard line placement assembly, a clamping assembly, a cutting assembly, a guide rail and a running assembly. The hard line placement assembly is arranged at the left end of the base and comprises a tray, a vertical pillar, springs and arc plates, wherein the tray is horizontally arranged and installed on the base rotationally; the vertical pillar extends upwards from the center of the tray, the multiple arc plates are arranged on the periphery of the vertical pillar, and each spring is arranged between the corresponding arc plate and the vertical pillar; the clamping assembly is arranged on an installation plate at the right end of a guider and used for clamping the hard lines; the cutting assembly is arranged on an installation plate at the right end of the clamping assembly and used for cutting the hard lines; the running assembly is used for tensing the hard lines. The electric line paying-off fixed-length cutting device can achieve straightening and fixed-length cutting of the hard lines, thereby relieving labor intensity for people. The work efficiency is high.