The invention discloses chiral monophosphine ligand HP-Phos of a diphenyl ether skeleton, and a preparation method and application thereof. The chiral monophosphine ligand is a compound 1, or an enantiomer, a racemate and a diastereomer of the compound 1. The preparation method of the ligand includes taking compounds as shown in the specification as raw materials, and subjecting the raw materialsto substitution reaction, coupling reaction, addition reaction, condensation reaction and reduction reaction to prepare the ligand; or taking compounds as shown in the specification as raw materials,subjecting the raw materials to condensation reaction to obtain reactants, subjecting the reactants and a compound as shown in the specification to addition reaction to prepare the ligand. Through theaddition reaction between the compounds with two configurations and different types of metal reagents, the chiral monophosphine ligand, namely an optically pure compound with four general configurations of 1(S, Rs), 1 (R, Rs), 1 (S, Ss) and 1 (R, Ss) can be obtained. The invention further discloses the application of the ligand in copper-catalyzed reaction between hydrazone compounds and hydrogenphosphide. The ligand has high reactivity and stereoselectivity and wide application value.