Abstract: In order to solve the phenomenon of turpentine overflow that often occurs during the use of Pinus sylvestris var. mongolica, surface degreasing and silanization closure treatments was carried out on Pinus sylvestris var. mongolica. First, the wood was degreased by cooking with different mass concentrations of sodium laureth sulfate (AES) compound emulsion, and then the degreased wood was closed with methyltrimethoxysilane (MTMS) solution hydrolyzed for different time. The degreasing rate and overflow rate were measured, the degreasing mechanism was discussed, and the surface chemical structure, wettability, and mechanical properties of control, degreased and degreased-closed wood were analyzed. The results showed that the degreasing rate increased with the increase of AES concentration. When the AES concentration was 2.5%, the degreasing rate reached 39.0%, and the fat spillage rate was only 1.0%. Low surface energy Si—CH₃ characteristic absorption peaks appeared on the surface of the degreased-closed wood, and the contact angle between water and oil on the surface as well as the static stability increased with the increase of the hydrolysis time of MTMS. The 24 h water absorption of degreased-closed wood, which was (60 ± 5) %, decreased significantly compared with the control wood, which was (51 ± 4)%, and the compressive strength parallel to the grain increased slightly.