Abstract: In this paper, the machining properties of Mytilaria laosensis with same stand condition and different tree age of 7, 14, 21 and 28 years in Pingxiang, Guangxi, were tested with weighted integral. The effects of tree age and height on wood machining properties were compared.The results showed that with the increase of tree age, the mechanical processing performance of M. laosensis wood improved, the proportion of planning, shaping and mortising were gradually improved as well. The proportion of sanding level 1 rose first and then fell back. There was no difference in boring performance. At the same age of wood, planning performance at the upper end was better than that at the lower end. Sanding and shaping performance were just the opposite. According to the comprehensive score of mechanical processing performance, the processing performance of M. laosensis was optimal when it grew to 21−28 years.