The invention provides a thermal
processing method of timber and belongs to the technical field of the heat treatment of timber. The specific procedures are: (1) the timber is placed in a heat treatment chamber by
yard; (2) the temperature and
oxygen content of the first stage are set, namely, the temperature is 80-150 DEG C and the
oxygen content is 12-21%, the
treatment time maintains 0.5-1.5 hours for each
centimeter thickness of the timber; (3) the temperature and
oxygen content of the second stage are set, namely, the temperature is 150-200 DEG C and the
oxygen content is 6-12%, the
treatment time maintains 0.5-2 hours for each
centimeter thickness of the timber;(4) the temperature and
oxygen content of the third stage are set, namely, the temperature is180-260 DEG C and the
oxygen content is 2-6%, the
treatment time maintains 1.5-2 hours for each
centimeter thickness of the timber; (5) the fourth stage is a cooling and
equalization treatment stage, the indoor temperature is lowered to less than 100 DEG C, then
equalization treatment on the water ratio of the timber is carried out in the way of spray-
steaming, then the temperature is lowered to 40-50 DEG C after the water ratio of timber meets the product requirement, and the treated timber is taken out. The method can prominently reduce the problems of the prior art that the
strength loss is serious with a great deal of defects.