This paper employs YSO crystal arrays and MPPC arrays to construct a nuclear radiation imaging detector, investigating the key factors influencing the performance of MPPC array-based nuclear radiation imaging detectors, including front-end resistance networks, light guide thickness, and light guide edge cutting depth. Initially, through front-end electronics experiments, it is found that using symmetric charge division circuit (SCD) can improve image distortion issues and enhance signal-to-noise ratio. Subsequently, based on SCD, the impact of different thicknesses of light guides (0, 1.0, 1.5, 2.0, 2.5 mm) on imaging performance was studied. The results show that a thickness of 1.5 mm provides the best resolution. However, the edge pixels of the crystal array still cannot be distinguished. Lastly, building upon the 1.5 mm light guide, experiments cutting the light guide periphery to varying depths and inserting enhanced specular reflector (ESR) demonstrats that complete cutting through with the addition of reflective film allows for clear distinction of edge crystal units.