A multichannel coherent receiver testing system has been designed, which based on the Visual Studio. It consists of the modules which are provided by the Keysight Technologies CO., LTD, including digital receiver M9703A, signal source M9380A (made of the source output M9301A, phaselocked loop M9310A and frequency reference M9300A), Quad downconverter M9362A, IF Amplifier/Attenuator M9352A and Power meters M1911A. The system can be controlled on PC by program designing, and it makes the measurement convenient finish sixteen coherent channels testing. The system is stable and performing well, the amplitude error is less than 0.1 dB, the phase error is less than 1 degree.