This paper proposes a normalized-constrained approach for the joint clearance design of deployable overconstrained Myard 5R mechanism. Firstly, the overconstrained mobility characteristic of Myard 5R mechanism is analyzed, we show that the dimensional requirements are critical for this mechanisms such that the joint clearance is necessary and inevitable in the design process. Secondary, the normalized-constrained model of Myard mechanism without changing its deployable ability is proposed by attaching two revolute joints along the two short links of the original Myard mechanism, we show that this normalized-constrained mechanism is still deployable/foldable to the appropriate deployed/folded configurations under some possible dimensional errors. Thirdly, the clearance model for revolute joint is created, then we can calculate the optimized joint clearance based on the motion range of the two additional revolute joints in the normalized-constrained model. Finally, a design example is given to show the detailed design procedures of methodology proposed in this paper.