Abstract: The present disclosure provides a fiber laser light coherent combination system, comprising: a modulator module configured to perform a phase modulation on sub-beams according to pseudo-random sequences orthogonally independent from each other, and perform a frequency shift on a reference beam according to a set frequency; a fiber laser light amplifier module configured to perform a power amplification on the modulated sub-beams; a laser light collimation emission module configured to collimate and output the sub-beams and the reference beam; a combination sampling module configured to perform a combination of the sub-beams and the reference beam which are collimated and outputted, and convert them into an electrical signal; a digital phase modulation and demodulation module configured to perform a demodulation on the electrical signal according to the shifted frequency and each of the pseudo-random sequences, and obtain a phase difference between each of the sub-beams and the reference beam.