The study aims to describe the inherent complex dynamic characteristics of mast mechanism of rotary drilling rig synthetically and improve the smooth going performance of key parts and related hydraulic system in the lifting process for mast mechanism.A dynamic model of mast mechanism is first established with Newton Euler method,and then a hydraulic system model of mast mechanism based on power bond graph is built up. A set of optimal installation position parameters are obtained through analyzing and comparing the impact of the dynamic characteristics due to changes of the installation position of mast mechanism in the lifting process.The integrated modeling method provides a certain theoretical reference for designing the mast system of rotary drilling rig.