The Non-Line-Of-Sight （NLOS） imaging process was studied to figure out the performance of existing NLOS algorithms under different reflection characteristics， with adopting physically based rendering bidirectional reflectance distribution function. Two state-of-the-art algorithms named f-k algorithm and Light-Cone Transform （LCT） algorithm are considered in the reconstruction using the proposed simulation system. The performance of the two algorithms are analyzed under various roughness， angles and niose. The simulation results show that： the change of reflection characteristics has a greater impact on the LCT algorithm； noise has a greater impact on the f-k algorithm. Based on the analysis of the experimental results， this article proposes an improvement to the f-k algorithm， merely using the phase information of the measured data for NLOS reconstruction. Improved algorithm is cpable to reconstruct target objects with different reflection characteristics， providing help for exploring further study.