Using high-performance polymers to replace the weak points in wood may be an efficient approach to overcoming certain drawbacks while improving the properties of wood. This study investigated the feasibility of easily replacing part of the wood matrix in poplar wood with renewable poly(furfuryl alcohol) (PFA). The wood was first treated with an alkali solution and was then immersed in a furfuryl alcohol (FA) solution followed by in situ polymerization. After delignification, a large part of hemicelluloses and lignin were removed. In addition, wood porosity increased and more PFA was polymerized in the wood cell walls, resulting in increased weight percent gain and efficient bulking. The thermogravimetric analysis results indicated that the reformation strongly affected the wood thermal stability. A transformation with 30% FA maintained the porous structure of the wood and resulted in the highest maximum degradation temperature. The dynamic mechanical analysis results also indicated that reformation allowed for greater stress transfer at the interface and resulted in a lower damping peak and a higher storage modulus. Our approach, therefore, could provide a promising method to enhance the performance of wood by reforming the wood components and structures.