Based on the evanescent waves of microring resonance next to the waveguide and the bus waveguide， an optofluidic device composed of the chalcogenide semiconductor Sb₂Se₃ was proposed. The function of device could be actively modulated by the phase change of Sb₂Se₃， so that the device could realize two different functions under the condition of single wavelength input. Spherical and rod-shaped polystyrene particles were used as model systems， in which spherical （0.5 μm in diameter） and rod-shaped （0.5 μm in diameter and 1.5 μm in length） polystyrene particles could simulate Staphylococcus aureus and rod-shaped Escherichia coli， respectively. These two different bacteria were used to implement the shape-sorting function of the device. By heating Sb₂Se₃ to the crystallization temperature（T_C = 200 ℃）， the materials of the waveguide and the resonant ring were phase-transformed， and the device could be tuned to switch between the two functions of storing particles and sorting particles. The protocol may provide a reference for shape-selective screening of biomolecules and meet the requirements of a new generation of lab-on-a-chip technology.