The time-dependent autogenous shrinkage of shotcrete under different alkali content and dosage of accelerators was tested. The adiabatic temperature rise, microstructure, chemical compound, and mercury injection test were characterized to determine the influence of accelerators on the autogenous shrinkage of shotcrete. The previous theoretical model for shrinkage was improved by introducing the influence factor of expansive hydration products. An autogenous shrinkage prediction model suitable for shotcrete was proposed, and the relevant model parameters were calibrated based on experimental results. Compared with the control group, alkali-free or alkaline accelerator significantly accelerates the autogenous shrinkage of shotcrete, which is mainly due to the accelerating effect on the hydration process at an early age and the free water absorption in the hydration process; Compared with the alkaline accelerator, alkali-free accelerator generates a large amount of expansive hydration product Ettringite. Therefore the autogenous shrinkage of shotcrete with alkali-free accelerator was smaller than that with alkaline accelerator. By introducing the influence factor p 1 the previous shrinkage model was improved. The new model can better describe the influence of expansive hydration products generated by accelerators on the shrinkage of shotcrete. The theoretical model is suitable to investigate the shrinkage development of the initial tunnel support structures.