This paper presents TRx modules based on microwave photonics developed by Tsinghua University and their application in ISAR. The Tx module is based on OAWG, and can produce signal with arbitrary waveforms on the demand with its frequency tuneable from GHz to 100GHz. its bandwidth up to 10GHz, and its maximum duration up to the order of millisecond. The Rx is a coherent frond end with its central frequency tuneable and its bandwidth reconfigurable to match the Tx. With the TRx, an ISAR experimental system is building up. imaging results show it has a range resolution of 5 cm and a velocity resolution of +/-2m/s in the case of TRx working at X band with the bandwidth of 4GHz.