Based on the traditional three degree of freedom（DOF） planar parallel mechanism， a novel reconfigurable 3-DOF planar parallel mechanism is proposed. Firstly， based on the theory and method of topology design of the parallel mechanism position and orientation characteristic （POC）. The switch between the 3-revolute-joint，prismatic-joint，revolute-joint（3-RPR） and 3-revolute-joint，revolute-joint，revolute-joint（3-RRR） planar parallel mechanisms is realized through a reconfigurable branch chain. Then， taking 3-RRR configuration as an example， the important topological indexes of the mechanism， such as POC， DOF and coupling degree， are analyzed. Based on the structural characteristics and geometric constraints of the mechanism， the inverse kinematics model is derived by using the closed vector method. Finally， the position workspace of the mechanism is analyzed based on the geometric constraint method of the branched chain and the inverse solution model respectively. This work provides not only a new idea for the analysis of mechanism workspace， but also a new choice for the design of mechanism.