The work aims to design the six-bar mechanism for the medicine package sealing machine to enable the mechanism’s output component, the slider to make rectilinear motion, so as to complete linear edge sealing. According to the functional relationship between the bar length and the angle when the linear sealing mechanism was at the limit position, ADAMS parametric modeling function was used to calculate the initial values of each angle. The virtual prototype model was built at the limit position and the motion simulation and analysis were carried out. Based on the simulation analysis, the placement of slider was 278 mm, the maximum speed was 1160 mm/s, and the acceleration curve rate was 0.7~0.9 s. The sealing effects would not be affected because of the back tracking. The linear sealing mechanism ran smoothly. It is simple and feasible to establish parametric model through limit positions, and such method can be applied to the parametric modeling of other complex mechanisms.