The rheological behaviour of cemented paste backfill (CPB) has an important influence on the stability of its transportation in pipelines. In the present study, the time-dependent rheological behaviour of CPB was investigated to elucidate the effects of time and solid content. Experimental results showed that when CPB is subjected to a constant shear rate, the shear stress gradually decreases with time before finally stabilis ing. When the solid content was 60%~62%, a liquid network structure was the main factor that influenced the thixotropy of CPB, and the solid content had less influence. When the solid content was 64%~66%, a floc network structure was the main factor that influenced the thixotropy of CPB, and the solid content had a more significant influence on the thixotropy than the shear rate. The initial structural stability of CPB increased with the solid content, and this relationship can be described by a power function. Based on the experimental results, a calculation model of pipeline resistance considering thixotropy was proposed. The model was validated by using industrial experimental data. The current study can serve as a design reference for CPB pipeline transportation.