In order to study propagation characteristics of Gaussian-Schell model Gaussian-Schell model(GSM) pulses in single-mode fibers, the characteristics of GSM pulses propagating through the single-mode fibers were studied by means of temporal coherence function propagation analysis. Based on the analytical expression of temporal coherence function, the changes of pulse width, coherence time and power spectrum were analyzed. The generalized van Citter-Zernike theorem in time domain for single-mode fibers under remote conditions is also derived. The results show that there are two conserved quantities of power spectrum and global coherence in the transmission of GSM pulses in single-mode optical fibers, and they are consistent. The study has important theoretical and practical significance in the field of laser transmission.