In order to study the influence law of the inner sleeve material properties and geometric dimensions on the pre-tightening force，this paper firstly studied the influence law of different inner sleeve material and wall thickness on the pre-tightening force through experiments. Then， the numerical model of the joint pre-tightening force was established by the finite element software ANSYS， the simulation results were in good agreement with the experimental values， and the experimental phenomena were analyzed by the finite element. The results show that under the same extrusion amount，the higher the joint wall thickness， the higher pre-tightening force generated； for the inner sleeve joint of plastic material， when the external extrusion amount exceeds a certain value， the plastic material completely enters plasticity and deforms increase， but the stress value no longer increases significantly， and the pre-tightening force tends to be stable；for the inner sleeve joint of elastic material， the elastic material stress has been increasing linearly with the strain， so the pre-tightening force continues to increase with the increase of the extrusion amount.