The invention relates to a flexible rope drive device with an automatic rope take-up function. The flexible rope drive device comprises an optical-electric encoder, a permanent magnet direct-current torque motor, a front support, an electromagnetic brake mechanism, a brake flange, an epicyclic gear train, a transmission shaft, a winding drum, a flexible rope, a force measurement guide mechanism, aflexible rope guide mechanism, an automatic rope take-up mechanism, a rear support, a top plate, a wearing ring, a bottom plate and a side plate. The electromagnetic brake mechanism is powered on, aninner gear ring is braked, the epicyclic gear train is a planetary gear train, the permanent magnet direct-current torque motor drives a sun gear to rotate, and after reduction of the planetary geartrain, a flexible rope is taken up and paid off under control of the motor. The electromagnetic brake mechanism is powered off, the inner gear ring is separated from brake, the epicyclic gear train isa differential gear train, a planet carrier is not controlled by the motor, the winding drum rotates reversely under the action of resilience of the automatic rope take-up mechanism, and the automatic rope take-up function is achieved. The flexible rope drive device can have the functions of rope take-up and pay-off controllability, automatic rope take-up, force measurement, rope jumping prevention and the like at the same time, overall modular design is achieved, the structure is compact, energy consumption is low, the flexible rope is wound regularly and orderly, and the work efficiency ishigh.