Aiming at deviation control in vertical gas well drilling， designed is a set of special stabilizer for gas well drilling and applied is the finite element simulation software to simulate and analyze mechanics characteristics of pendulum drill assembly in the special stabilizer for gas well drilling. Considering such parameters as pendulum drill assembly structure parameters， borehole parameters and drilling parameters， discussed are relationships between stabilizer fluctuation spacing， stabilizer and bit distance， drilling pressure， well deviation angle and stabilizer fluctuation size and drill pendulum force and analyzed are effects of various parameters on the drill pendulum force. The calculation results are basically consistent with those obtained by using crossbar bending beam theory in the same conditions. A series of analysis results show that the pendulum drill assembly of the special stabilizer has strong ability of deviation control and can effectively control deviation in vertical gas well drilling.