Abstract: The difference of sensitivity among different optocoupler techniques under the total dose degradation and the displacement damage should be duly considered when using these components in LEO spacecrafts. This paper analyzes the radiation effect of the LED part, the photodetector and the amplifier stage inside the optocouplers under both the total dose and the displacement radiation environments, and makes a sensitivity comparison of different parts and technologies. Based on the ground radiation test results, the on-orbit verification circuits are designed, and experiments of three kinds of typical optocouplers under low earth orbit are conducted. The experiment results indicate that these optocouplers could meet the requirements of low earth orbit applications under suitable parameters and with appropriate electric circuit design.