In this paper, the noise and readout modes of space infrared telescopes are analyzed first. Then, the principles of four signal sampling techniques are introduced respectively: C correlated double sampling, Fowler sampling, slope sampling, and multiple accumulation sampling. On this basis, the advantages and disadvantages of four signal sampling techniques are compared and analyzed in four aspects, such as detector readout mode, noise reduction, data volume, and cosmic ray detection. Finally, the selection strategy of foreign space infrared telescope signal sampling technology is given, which is expected to serve as a reference for the development of China′s space infrared telescope.