Abstract: In this paper, Pinus massoniana wood was taken as study object. By adopting a process of different hydro-thermal treatment temperature (140 ℃, 160 ℃, 180 ℃, 200 ℃) and different time (1 h, 3 h, 5 h), this paper analyzed the dimensional stability and color changes of P. massoniana wood after being hot-water treated. The main conclusions of this paper are concluded as follows: The quality loss rate of P. massoniana lamb wood increase with the increase of temperature and time gradually, and the equilibrium moisture content decrease with the increase of temperature and time gradually; After the high temperature hydro-thermal treatment of different processes, calculation of the anti-inflation rate is negative in wood processing, the absolute value of the expansion rate with high temperature hydrothermal treatment time prolonged, the temperature gradually increases, therefore wood dimensional stability after treatment showed increasing trend; With the increase of treatment temperature and time, the color of P. massoniana wood gradually changed from light yellow to dark brown.