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quantitatively analyzed the mechanical interlock force, friction force, and interfacial bonding force between deformed bar, plain bar, plain Al-alloy, and concrete. Some scholars found that the external force is transferred to the surrounding rock masses through the interfacial bonding force, mechanical interlock force, and friction force among the bolt, anchorage agent, and surrounding rock masses under pull-out test, so as to achieve the anchorage equilibrium and reinforce rock masses. The rock bolts anchoring system is a composite material system consisting of three materials and two interfaces. In the past few decades, rock bolts and cable bolts support technology have become the main means to strengthen surrounding rock strength in the fields of construction, water conservancy, underground space, and so on, with the advantages of low cost, high reliability, and high carrying capacity. This paper leads to a better understanding of the load transfer mechanism for the anchoring system in soft and hard composite strata and provides a reference for scientific support design and evaluation method. Under the same anchor length, the peak load and the displacement at the peak load decrease with the increase of layer numbers, but the reduction magnitude decreases. The greater the hard rock thickness, the larger the peak load. Therefore, the closer the hard rock is to the loading end, the greater the initial stiffness of the load-displacement curve is. As the hard to soft thickness ratio increases, the load peak and the displacement at the peak load increase. The load-displacement curve shows the same initial stiffness for different hard to soft thickness ratios in HSCRS. As the soft-to-hard thickness ratio in SHCRS increases, the initial stiffness of the load-displacement curve and peak load decreases continuously. Under the same layer number, the shallower-soft and deeper-hard composite rock strata (SHCRS) have a higher bearing capacity and deformation resistance than the shallower-hard and deeper-soft composite rock strata (HSCRS). Lithological sequence, layer thickness ratio, and layer numbers are taken into consideration in numerical simulation models. The numerical result shows a close match with the experiment tests and the proposed model. Then, the nonlinear bond-slip relationship is put into the numerical model. The nonlinear bond-slip relationship of bolt-grout interface that is anchored in soft rock and hard rock is obtained from laboratory test, respectively. A numerical study is presented in this paper on the pull-out behavior of fully grouted rock bolts in soft and hard composite rock strata. However, most of the current support is designed for homogeneous rock masses, which ignores the different anchoring effect in soft and hard composite rock strata. Soft and hard composite rock strata are frequently encountered in transportation, geotechnical, and underground engineering.