The invention provides an optical fiber parameter calculating method and device, and aims to obtain optical fiber parameters via calculation. The invention further provides a phase sensitive amplifier and a full-optical phase regeneration device, wherein the phase sensitive amplifier is used for regeneration of full-optical phase; the involved optical fiber is obtained by using the calculating method and the calculating device. The optical fiber parameter calculating method comprises the following steps: acquiring signal optical waves, first pumping optical waves and second pumping optical waves, performing four-wave mixing in an optical fiber of double-pump degeneracy PSA so as to generate four sideband-idle optical waves, establishing a 7-wave value model, and dissolving a coupling equation of the signal optical waves, and calculating so as to obtain vibration amplitude phase of the regenerated optical waves; adjusting non-linear phase shift and optical second-order dispersion coefficients, so as to obtain the minimum and optimal optical second-order dispersion coefficient corresponding to non-linear phase shift. The optical fiber is manufactured according to the parameter, the optical fiber is applied to PSA, then the PSA has relatively large GER and works in relatively small non-linear phase shift, and furthermore, a regeneration device of low power consumption and full optical phase can be obtained.