The invention provides an ocean salinity satellite based on joint detection of multiple remote sensors, Moreover, the multiple remote sensors are arranged to detect the ocean salinity synchronously, and the multiple remote sensors are arranged on a platform of an ocean salinity detection remote sensing satellite, and at least comprise an L wave band two-dimensional synthetic aperture microwave radiometer, an L wave band one-dimensional synthetic aperture microwave radiometer, an L wave band digital beam forming scatterometer, a C wave band microwave radiometer, a Ku wave band microwave radiometer, and a K wave band microwave radiometer. Therefore, the means of joint observation and reversed return observation is adopted, the combination of high resolution and high stability is completed, and the ocean salinity satellite also has the capability of accurately adjusting the brightness temperature of an L wave band through the reversed return observation data. At the same time, a plurality of frequency bands of a one-dimensional synthetic aperture and the scatterometer share a same cylindrical reflector antenna, so that the complexity of a system is reduced.