Initially， the robot’s Hunt singular surface equations are derived by using the criterion where the three linkages intersect at a single point. It is discovered that the Hunt singular surface equations of the 3-revolute-joint，prismatic-joint，revolute-joint （RPR） planar parallel robot are completely identical to the output singular surface equations obtained using the Jacobian algebraic method， meaning the two surfaces coincide. Furthermore， four commonly occurring types of Hunt singular configurations in the robot are identified， and their singular trajectories are depicted on the singular surface， helping to reveal the relationships between these singular configurations. Subsequently， three special structures of the 3-RPR planar parallel robot are designed， and their Hunt singularities are analyzed. The results show that the robot's Hunt singularity characteristics are highly dependent on its geometric structure. Finally， the existence of Hunt singularity in the 3-RPR planar parallel robot is demonstrated through experiments with both virtual and physical prototypes.