Shanghai Soft X-ray Free Electron Laser (SXFEL) is the first fourth-generation light source in China that can work in soft X-ray band. With the advantages of short wavelength, full coherence, ultra-high brightness, and ultra-short pulse, it is expected to play an important role in basic science research. Based on the characteristics of the linear accelerator, the stripline beam position monitor (SBPM) was selected as the beam position measurement tool in the injection section and the straight section. The system is mainly composed of the probe, the front-end electronics system, and the digital beam position monitor (DBPM). The design draws on the same type of device from Shanghai Synchrotron Radiation Facility (SSRF) and is further optimized according to the characteristics of SXFEL. Finally, the beam experiment results show that the resolution reaches 5.7 μm@188 pC, which meets the requirements for beam position resolution of SXFEL.