Infrared synchrotron radiation provides considerable brightness advantages over conventional infrared sources in a wide wavelength range, allowing the spatial resolution to reach the diffraction limit. Spatial resolution of BL01B1 infrared microspectroscopy beamline station in Shanghai Synchrotron Radiation Facility (SSRF) is tested. Step-edge method and resolution target bar method are used to measure the spatial resolution of the infrared microspectroscopy beamline BL01B1. The experimental results show that the spatial resolution of this infrared microspectroscopy beamline station and the diffraction limit theory are comparable in the middle infrared region.