The influence laws of impregnation pressure and time on the weight gain rate (WPG) of poplar wood were systematically investigated by using special equipment for vacuum pressure impregnation of wood processing. The results show that the effects of the impregnation pressure and time on the WPG had great influences; With the increases in pressure and temperature and time, the WPG tended to sharply increase atfirst and then to gently grow, and the hightest WPG went up to 36.6%; Based on the comprehensive consideration of saving time and energy costs, it is suggested that the optimized impregnatio...