The invention relates to a purpose and a method of an amido-contained neutral phosphine extracting agent for extracting and separating zirconium and/or hafnium. The amido-contained neutral phosphine extracting agent is expressed as the following formula I: FORMULA, wherein R1 and R2 are respectively and independently selected from C1-12 alkyl; R3 and R4 are respectively and independently selected from C1-3 alkyl and hydrogen; R5 and R6 are respectively and independently selected from C1-16 alkyl and hydrogen; and at most one of R5 and R6 is hydrogen. The amido-contained neutral phosphine extracting agent expressed as the formula I serves as a neutral phosphine extracting system for forming a main extracting agent to mix and extract with zirconium (IV) and/or hafnium (IV)-contained liquid; and then, such steps as extraction and reverse extraction are performed to respectively obtain zirconium or hafnium-contained solution or precipitates. The result shows that the purity of the finally obtained zirconium is higher than 99.99%, the content of hafnium in zirconium is lower than 80 ppm, in particular lower than 10 ppm; the purity of the obtained hafnium is higher than 99.0%, the content of zirconium in hafnium is lower than 0.1%; and the separation and the purification of zirconium and hafnium are effectively realized to achieve the use standards of atomic energy level zirconium and hafnium.