Recently, solid wood furniture has become the new direction for the development of Chinese furniture industry. In order to realize solid wood customization, the standardization of solid wood parts is a problem for high priority. In this study, a standardized experimental study on children’s solid wood furniture parts was carried out by using group technology. Twenty pieces of children’s solid wood furniture were selected, including 1084 parts in total with 705 solid wood parts. Then, three key structural features of the parts were analyzed based on the processing similarity principle, including the center line of the long side direction of the parts, the shape of the outside surface of the long side direction and the shape of the outside surface of the short side direction. Moreover, these parts were classified according to the principle of process similarity. Accordingly, a children’s solid wood furniture parts family was established, and the distribution of parts in the family was analyzed. In detail, the parts with the dimensional difference within 2 mm were combined, the dimensional value was mainly based on the value of most parts before the combination and part specifications were optimized on the basis of the original specifications or its 1/2 method. The results show that the category of thickness specification reduced by 20, and the number of parts included in one thickness specification increased by 2.2 times on average. Moreover, the category of width specification reduced by 12, and the number of parts included in one width specification increased by 1.47 times on average. This not only greatly improves the degree of standardization of solid wood parts but also provides theoretical and practical basis for the digital design of mass customized children’s solid wood furniture.