Archaeological wooden objects excavated from Gansu are generally rotten and show typical corrosive characteristics due to the unique geographic environment and climate. Usually, wood objects are unstable to the outside environmental elements due to their wooden character and structure. The burial site, excavation process and museum environment all affect the decay of wood. Based on the current state of preservation of rotted wood objects from Gansu, the burial site conditions, museum environment and the influencing factors of exterior environment were investigated; the process and effect of environmental factors were analyzed; and the process and cause for deterioration were revealed. The mechanism of environmental corrosion includes the following factors. 1) Deterioration due to visible light and ultraviolet radiation, namely photochemical reaction in cellulose, leading to the breakage of cellulose chains and the production of several new compounds. 2) Decay of cellulose, which is stable at room temperature, but becomes unstable with increase in temperature, being oxidized in the presence of both high temperature illumination and oxygen. The presence of water, visible light, oxygen, enzymes, acidic or alkaline environment and high temperature accelerated the deterioration of rotten wood. 3) Soluble salts deteriorate the rotten wood by deliquescence and crystallization. 4) Mold, microbes and other pests harm wooden objects by secreting enzymes that decompose organic compounds in wood. 5) When the relative humidity was above 70%, the dust in the air deliquesces. When the dust settled on the surface of rotten wood, it can lead to the deterioration and decomposition of cellulose.