The invention relates to the field of steel material production and discloses a low nitrogen steel material and a preparation method and application thereof. The preparation method comprises the steps that a 1Cr21Ni5Ti steel ingot is subjected to forging of two-time upsetting and two-time pulling, then forged by a precision forging machine, and the total deformation rate of precision forging machine forging is 50%-80%; precision forging machine forging comprises 3-5 passes, and the deformation rate of the penultimate pass of precision forging machine forging is 35%-40%. According to the low nitrogen steel material obtained by the method provided by the invention, carbon nitride class B is smaller than or equal to 2 grades, carbon nitride class D is smaller than or equal to 2.5 grades, and even if under the condition that the nitrogen content of the steel material is low, it is guaranteed that the yield strength R0.2 of the steel material can meet the high requirement of an aerospace engine for materials.