The invention discloses an optical sensing device for restraining a voltage sensor temperature error and belongs to the field of an optical voltage sensor. The optical sensing device comprises an optical transmission unit and a Pockels phase sensing unit. The reciprocity degeneration of the Pockels phase sensing unit is caused by the inconsistency of the temperature fields and stress fields of two crystals; and the generation of a measuring error of the optical voltage sensor is caused by the influence of the non-ideal welding angle and counter shaft angle of the optical transmission unit on the magnitude of interference light intensity and feedback phase. By establishing a temperature error model of the optical transmission unit and the Pockels phase sensing unit, a novel optical base structure for counteracting additional stress birefringence in the two crystals is designed, and an angle error compensating method is provided, so that the measuring precision and temperature stability of the optical voltage sensor are increased.