Double-side solar cells refer to the ones which can absorb light and translate the light energy into photoelectric voltage and current in the both sides. Nowadays there are no perfect test specifications available due to they have many different structures. In this paper, the relationship between back side reflectivity and comprehensive conversion efficiency of solar cells was analyzed with using variable controlling method and PC1D simulating environment. Many parameters including voltage, current, power and efficiency were experimented under different back side reflectivity. Based on these experiment results, effective test conditions of double-side solar cell are given and complete test solutions are also presented. The conclusions bring significance to the development and application of double side solar cells.