In order to enhance the laser efficiency of dye-doped cholesteric liquid crystals, cholesteric liquid crystal is switched on and off by electric field and then treated by doing rubbing on the surface. The results show that the laser efficiency can be enhanced after the rubbing treatment no matter the thickness of cholesteric liquid crystal sample is thin or thick. Moreover, the laser efficiency in a thicker sample is increased more obviously. The reason is that, before rubbing treatment, liquid crystal molecules deviate from the ideal alignment direction. As a result, more or less defects are formed inside the samples, which induce light scattering and reduce its laser efficiency. More defects can be formed in a thicker sample, therefore, the optical loss induced by the light scattering is larger. Consequently, the laser efficiency in a thicker sample is decreased more compared with the ideal state. After the treatment, the alignment of cholesteric liquid crystal molecules is more or less improved and the optical loss caused by light scattering is reduced. The samples′ quality is improved and the optical loss is reduced more significantly for a thicker sample. Thus, the laser efficiency is enhanced, more significantly in a thicker sample after the treatment.