Altitude change is the gradient effect of multienvironmental factors. The fine root is an important organ for plants to absorb water and nutrients, and its characteristics are of great significance in indicating plant growth and distribution. In this study, the fine roots of spruce (Picea asperata) in the Gonggang Mountains at 2 500-3 300 m were taken as the research object. We used the root order classification method to determine the biomass and fine root morphology (average diameter, specific root length, root length density, specific surface area) of spruce to clarify the response of fine root biomass and morphological characters of spruce to altitude changes and the tradeoff between fine root functions. The purpose of this study is to provide a basis for explaining the structure and functional characteristics of a forest ecosystem. The results showed that: (1) the fine root biomass of spruce at different elevations increased with the increase of root order, and the biomass of 0-10 cm soil layer was significantly higher than that of 10-20 cm soil layer. (2) At different elevations and different soil layers, the diameter of 1-5 fine roots increased with the increase of root order, and the specific root length, root length density, and specific surface area decreased with the increase of root order. (3) Altitude had extremely significant effects on specific root length, root length density, and specific surface area, and among fine root traits, diameter had an extremely significant negative correlation with specific root length, root length density, and specific surface area, while had a significant positive correlation with biomass. The study shows that the effects of soil depth and spruce root order on diameter, specific root length, root length density, specific surface area, and biomass are not consistent, that is, there is heterogeneity in the response of root functional traits to environmental conditions.