The invention relates to a preparation method of a 
sacubitril intermediate having low 
triphenylphosphine oxide content. The preparation method comprises that water, 
isopropyl acetate, 
sodium bromide, 
sodium bicarbonate and tetramethylpiperidine 
oxide into (R)-tert-butyl(1-([1, 1'-
biphenyl]-4-yl)-3-hydroxypropane-2-yl)
carbamate, adding a 
sodium hypochlorite solution into the mixture drop by drop for a reaction, after the reaction, carrying out layering, taking an 
organic layer, adding ethoxyformylethylidenetriphenyl 
phosphorane into the 
organic layer, after a reaction, concentrating the 
reaction product, removing 
isopropyl acetate, adding 
ethanol, water and 
lithium hydroxide into the mixture, carrying out heating until 
reflux, carrying out concentration until 
drying, adding water and activated carclazyte into the product, carrying out stirring at the 
room temperature, filtering the mixture, adding 
ethanol and 
acetic acid into the filtrate, carrying out heating until 
reflux, and carrying out cooling and stirring to precipitate solids which are the 
sacubitril intermediate finished products. The preparation method can reduce 
triphenylphosphine oxide content of the (R)-tert-butyl(1-([1, 1'-
biphenyl]-4-yl)-3-hydroxypropane-2-yl)
carbamate.