Late Qing block-printed books, produced using woodblock printing during the late Qing Dynasty, are one of the key focuses of ancient book resource conservation and utilization. Ink loss often happens during routine browsing, digital scanning and restoration, and thus significantly affects the documentary value of ancient books, yet this problem has not received sufficient attention. In this study, we designed several assessment methods for the ink loss problem of ancient books, surveyed the degree of ink loss of more than twenty late Qing block-printed books, and conducted a preliminary analysis of the causes of ink loss according to actual restoration practices. As a result of this work, it is recommended that block-printed books suffering from severe ink loss be conserved using the brushing and wrapping methods. This study has practical reference significance for the conservation of ink marks of ancient block-printed books.