The invention provides a telaprevir intermediate preparation method. The telaprevir intermediate preparation method comprises the following steps: (1) synthesizing (3aR, 6aS)-1,3a,4,5,6,6a-hexahydrocyclopentapyrrol; (2) synthesizing (3aR, 6aS)-octahydrocyclopentapyrrol-1-sodium sulfate; (3) synthesizing (3aR, 6aS)- octahydrocyclopentapyrrol-1-cyanogen; (4) synthesizing (3aR, 6aS)- octahydrocyclopentapyrrol-1-carboxylic acid; (5) synthesizing (3aR, 6aS)-2-Boc octahydrocyclopentapyrrol-1-carboxylic acid; (6) synthesizing (1s, 3aR, 6aS)-2-Boc octahydrocyclopentapyrrol-1-carboxylic acid; (7) synthesizing (1s, 3aR, 6aS)-2-Boc octahydrocyclopentapyrrol-1-carboxylic acid ethyl ester salt. The telaprevir intermediate preparation method is reasonable in process, low in cost and simple and convenient to operate, reagents are inexpensive and easy to obtain, and the control on reaction is easy.