How to realize the accurate measurement of Sparameters of microwave devices has been the difficult technical problem of the industry, with one of main methods being making and using fixtures. This article introduces traditional kinds of fixture techniques, and then discusses the solution of fixture with TRL calibration, giving the designing method and matters needing attention of TRL calkits. A series of TRL calkits are produced and an experimental is designed, to prove that the method can calibrate the measurement error and improve the testing accuracy effectively.