The invention provides a power cable real-time state monitoring and operation management system and a measuring method of the temperature of a cable. The power cable real-time state monitoring and operation management system comprises a distributed Raman temperature measurement sensing unit, a data acquisition subunit, an optical magnetic field sensing unit, a current data demodulator, an FPGA core processing subunit, an ARM core processing subunit, a magnetic field sensing head and an operation management server, wherein a temperature demodulator of the distributed Raman temperature measurement sensing unit and the current data demodulator of the optical magnetic field sensing unit are connected with the operation management server through Ethernet interfaces, an optical filter carries out band-pass filtering processing on Stokes light and Anti-Stokes light, light intensity signals of filtered back Raman scattering light are converted into electric signals through a photoelectric detection unit, the electric signals are amplified to obtain voltage signals corresponding to the temperature, the data acquisition subunit carries out A/D conversion on the voltage signals, an actual temperature value is obtained through calculation, the hidden danger of faults, with unobvious surface temperature rise, of the cable is eliminated, real-time fault recording is carried out on important cable taps, rapid contact locating of the hidden danger of the faults and accident analysis are facilitated, and real-time calculation of the current-carrying capacity is achieved.