In order to make single chip birefringent crystal wave plate apply to two differ ent laser wavelengths,based on the principle of birefringent crystal phase retarder s,the relationship between the thickness of wave plate and the delay of two laser wavelengths is pr ovided,and the concrete design method is given;A sample was produced for t wo laser wavelengthsof 650nm and 780nm. The results show that for the double quarter wave plate,the quarter wave plate a t 650nm and the half wave plate at 780nm,the of the deviations delay are less than 3°,which are in accordance with the theoretical value.If we don′t care ab out the thickness of the wave plate,only in terms of design,the 1/4and 1/2wave plates for double laser wavelengths with high precision can be obtained.Thus,accordint to the design principle and method in t his paper,the wave plate for two laser wavelengths can be achieved by using the production method of conventional birefringent crystal wave plate.