Abstract: In order to improve the performance of wood in outdoor applications, the polyethylene wax with stable properties is applied to impregnate the commonly used wood under high pressure, and explore the stability of modified wood. The results showed that the whole section of the wood can contain wax by 3 stages of high pressure dipping. The wax content of modified wood was over 24%, and that of Pinus radiata was 58.5%; Artificial accelerated aging had little effect on the flexural properties of modified wood. After 30 days SEM observation of modified wood samples, it was found that accelerated ageing only occurred on the surface of the sample wood; Polyethylene wax has a certain protective effect on wood color. However, it faded slightly under the action of aging environment. The wood color stability of modified wood was significantly improved by adding ultraviolet absorber and antioxidant to polyethylene wax, and the total color difference ΔE was 4.139, compared with no additives, it decreased by 45.3%; In the natural durability test of wood, the modified wood had strong rot resistance and termite decay resistance. The durability of modified wood of P. radiata and Eucalyptus saligna upgraded from 0 grade to 9 grade, which can be used in outdoor landscape garden architecture.