In order to analyze the attitude adaptability of lubrication system,a kind of modeling and concealment calculating method according to STL incising technology was proposed for the complex components.The modeling database was carried out by this method,that is the relationship among liquid level,area,volume and the center of mass under the different attitude angle and acceleration.Binary spline interpolation was used to get the concealed oil under the specified attitude angle.Three examples were given to demonstrate the modeling error according to STL incising technology is within ±1.1% compared with UG and within ±8.3% compared with actual experiment.It significantly improves the efficiency of concealment characteristics analysis.The results of concealment characteristics analysis provide technical supporting for the analysis of the attitude adaptability.