The motion of up-dialing finger of beer bottle washer infeed mechanism was analyzed. The position coordinates of the finger in a motion cycle were obtained by using MATLAB. A three-dimensional model was set up for the mechanism and the calculation results were verified using ADAMS kinematic simulation. A precisely fit curve of guiderail for motion of up-dialing finger was determined according to the requirements of velocity limits on the mechanism. The purpose was to provide reference for bottle infeed guide-rail design.