Some methods of reducing losses of CPW were summarized.By using the HFSS software,we simulated the insert loss and return loss of CPW of these methods.Then the structure of using isolated SiO2 were chosen as the optimal method considering the characteristic of microwave power sensors,but there also existed some disadvantages in this method and was explained with the knowledge of semiconductor physics.Lastly,some improvements were brought forward,which were verified to be right by using HFSS.From the result of the simulation,the absolute value of insert loss is reduced below 0.6 dB and the return loss is reduced below-30 dB.