The natural characteristics of oil truckers under different filling rates are studied,and the influence of liquid sloshing on the inherent characteristics of oil truckers are focused on.The modal module and acoustic modal module in Workbench are used to carry out modal analysis on the tank body of oil tanker in the state of no-load,70%,85% and 100% filling respectively.Among them,the modal module is directly used to analyze the no-load tank;The acoustic solid coupling method is used to establish the wet modal model in the liquid filled state,and the acoustic modal module in workbench is used to carry out modal analysis.Finally,the six order natural frequencies and vibration modes of the different states are obtained.Comparing the obtained 6th order natural frequencies and vibration modes of several different states,it is known that the natural frequency of the tank will decrease with the increase of the liquid filling amount,and the liquid sloshing has a great impact on the tank system.