The business performance of the large grain-households has a direct impact on the production enthusiasm of farmers. It is of a great significance to explore the factors affecting the performance of the large grain-households. Based on a survey data of the large grain-households in the five central provinces and applying the regression analysis, this paper analyzed the influences of the human capital and the symbolic capital on business performance and discussed its response to the moderation of the scale degree. Results show that: the human capital of the large grain-households is divided into different categories, including “general”, “technical”, “managing” and “innovative”. The symbolic capital included “internal” and “external” categories. The average production scale of the large grain-households is 6.67 hm2, and the average score of business performance is 4.860. The business performance is at a medium level and there is a potential to further improve. The human capital and the symbolic capital have significant positive impacts on business performances. The scale degree has moderated the impacts of different types of the human capital and the symbolic capital on business performance. Compared with the large scale grain-households, when the scale of the large grain-households is small, the general human capital and the technical human capital have stronger impacts on business performance. The influence of the internal symbolic capital on business performance is stronger. Compared with the small-scale grain-households, the managing capital of those large-scale grain-households is large, and the managing human capital and the innovative human capital have stronger impacts on business performance. While the influence of the external symbolic capital on business performance is stronger. Results also indicate that the large grain-households can invest in different types of the human capital and the symbolic capital according to their operating scales to achieve the best performance returns. Therefore, it is proposed that local governments should encourage and guide the large grain-households to appropriately invest in the human capital and the symbolic capital and to increase the scale of production.