Taking the main bearings of marine low-speed diesel engines as the research object,the simulation analysis was conducted on the pre-tightening force of the main bearing during the installation process and the oil film pressure during the working process.The finite element method was used to solve the main bearing oil film pressure distribution.The finite element software was used to calculate the amount of deformation caused by the pretightened force when the bearing bush was installed.The stress and strain of the bushing caused by the oil film pressure was simulated with and without considering the pre-tightening force of the bushing.The results show that the maximum value of the deformation appears at both ends of the main bearing bush due to the pre-tightening force.The stress and strain produced by the pretightened force during the installation process of the bearing bush are relatively large,hich affects the effect of the oil film pressure on the bearing bush during the working process.Therefore,the influence of the pre-tightening force cannot be ignored when analyzing the stress and strain conditions of the main bearing.Pre-tightening force not only affects the stress and strain value of bearing bush,but also changes the rule of stress strain value.