Because a lot of defects will be formed in thick cholesteric liquid crystals (CLC), which destroys its photonic bandgap structure and dramatically reduces the transmissivity, its applications in photonics have been dramatically limited. In order to overcome this problem, we developed a method to improve the alignment of the liquid crystal (LC) molecules in the CLC sample. The procedure is as follows: firstly, high enough AC voltage with 1 kHz is applied to swithch on the CLC sample. After switching on and off the sample at this voltage for several times, massage is done on the CLC surface for a while. The results show that after massage, the defects inside the CLC sample can be dramatically reduced, therefore the planar structure of CLC is greatly improved, and the transmission is drastically increased. It indicates that this method can be used for fabricating thicker CLC samples. Above all, it provides a useful fabrication basis for the CLC′s applications in photonics.