With the application of millimeter wave radar in auto pilot, FOD detection and other fields, the performance of 92 ~ 96GHz (W-band) PA has attracted much attention. In order to solve the measurement of W-band PA, the paper presents a test scheme based on high-power frequency extender of VNA. Compared with other extenders, the high-power extender contains a build-in PA. The scheme can complete the measurement of all parameters in one measurement system. Compared with the traditional measurement of power parameters and small signal S parameters, it has the advantages of high system integration, simple measurement connection, one-time calibration to achieve all parameters measurement. It also can improve the repeatability of measurement. The paper presents the principle diagram of measurement setup, measurement procedure and some tips for measurement.