The invention discloses a method for measuring the included angle between the optical axis and reference plane of a satellite optical communication terminal, which relates to a method for measuring the included angle between the optical axis and reference plane of the satellite optical communication terminal and is suitable for measuring the included angle between the optical axis and reference plane of the satellite optical communication terminal. The invention aims to solve the problem of lack of measuring method reaching precision required for accurate aiming of emitted laser. The method is implemented by the following steps: 1, regulating a mirror 4 to make the optical axis of the mirror 4 coincide with the optical axis 1 of the satellite optical communication terminal 3; 2, calculating the included angles alpha1 and beta2 between the optical axis 1 of the satellite optical communication terminal 3 and the optical axis of an autocollimator 5; 3, regulating a parallel plain crystal6 to make the optical axis of the parallel plain crystal 6 coincide with the optical axis of the mirror 4; 4, making sure the state of the optical axis of the autocollimator 5 on the reference plane 2 of a measuring terminal coincides with the optical axis 1 of the satellite optical communication terminal 3; 5, obtaining the included angle between the optical axis 1 of the satellite optical communication terminal 3 and the reflection optical axis of the reference plane 2 of the terminal; and 6, conversion.