Abstract: The application of ecological farming technology is significant to ensure national food and ecological security, but the adoption rate at farmer level is still low. To explore the role of government promotion and social networks in improving the application of ecological farming technology, this study used Ordered Probit and Tobit models and a sample of 787 farmers from six major grain-producing provinces to empirically investigate the impacts of government promotion and social networks on farmers’ behavior of using ecological farming technology. This study contributes to the literature on the adoption of agricultural technology in two ways. First, we evaluated and compared the effects of government promotion and social networks on the adoption of ecological farming technology. Particularly, we investigated the moderating effects of heterogeneous social networks on government promotion, which is helpful in utilizing different channels of technology extension. Second, considering farmers’ use of ecological farming technology has changed from self-providing to outsourcing, we estimated the impacts of government promotion and social networks on farmers’ preferences for the outsourcing adoption of ecological farming technology. The main findings were as follows: First, although the direct impact of government promotion on farmers’ adoption of ecological farming technology was not significant, government promotion had a significant and positive impact on farmers’ adoption of ecological farming technology under the moderating effect of kinship networks. Second, government promotion had a significant and negative impact on farmers’ adoption of ecological farming technology, that is, it was not conducive for farmers to adopt ecological farming technology through outsourcing. However, relationship networks, especially kinship network, significantly weakened the negative effect of government promotion. Third, social networks played an important role in promoting farmers’ adoption of ecological farming technology. Whether it was the kinship or general network, it had a positive impact on farmers’ adoption of ecological farming technology, encouraging farmers to adopt the outsourcing of relevant technologies. However, the influence of the kinship network was greater than that of the general network. Based on the above findings, this study suggests that it is important to consider the heterogeneous and complementary effects of different social networks when promoting the adoption of ecological farming technology at the farmer level. In addition, it is helpful to use socialized services in agricultural production to promote ecological farming technology.