In order to solve the distortion problem caused by nonlinear effects on fiber optic communication signals during transmission and improve the stability of fiber optic communication systems, an improved k-means multi domain fiber optic communication nonlinear distortion compensation method is proposed. Build a multi domain optical fiber communication transmission model, use a wavelength converter at the transmission end to transmit the input signal to the fiber, and linearize the pulse recovery optical signal based on interference principle. Describe the dispersion char- acteristics of fiber optic communication using signal-to-noise ratio, and clarify the occurrence of nonlinear distortion changes in signal interaction. By improving the k-means method through the Dijkstra method, the distortion constella- tion is demodulated to avoid clustering falling into local optima, making all cluster signals as close as possible to the o- riginal modulation center, and achieving distortion compensation. The experimental results show that after compensa- ting for nonlinear distortion in fiber optic communication using the proposed method, the clustering effect is better, and the information error rate can be reduced to 10-7 , effectively reducing network transmission consumption and improving the quality of fiber optic communication signals.