The Tongsa(通事) refers to the interpreter, and the Tongsa group is an important medium for ancient Chinese diplomacy. The Joseon Tongsa was the Joseon interpreter official set up in the Qing Dynasty, was mainly responsible for Joseon Dynasty interpretation and communication, became a bridge and the bond of tributary relations between the Joseon Dynasty and Qing Dynasty. From the end of Kangxi to the early years of Qianlong, among the Xu's Tongsa family, especially the Xu Zongshun and Xu Zongmeng brothers are the most active. They mainly performed the duties stipulated by the Qing Dynasty, such as serveing as the ambassadors of Qing Dynasty to Joseon Dynasty, receiving the tributary Joseon envoys, supervising trade, interrogating and returning the drifters and the offenders, and so on. They play the role of communicate likings and needs and coordinate the etiquette of the two countries. At the same time, for personal survival and family building, they also disregard the Qing Dynasty's manage, relying on the role of interpreter, using power to violate the Qing Dynasty's regulations and seeking private interests, asking for and accepting bribes, participating in the Lantou(揽头) trade, the money obtained is used to set up the house and donated an official for his son, and was discovered and confiscated property by the Qing Dynasty. In the Qianlong period, with the stability of the Joseon-Qing relationship and the emphasis on the concept of "giving more and getting less" (厚往薄来),the flexible Tongsa used the role of interpretation to seek power to operate the space , causing dissatisfaction in the Qing Dynasty. Not only is it not satisfied with Joseon Tongsa's request for bribes, but it also has a negative sense of Joseon Tongsa's ability to interpret. As a result, the role of Joseon Tongsa was gradually weakened. Through the specific translation activities and power operation process of the Xu's family, we can re-examine the relationship between the Joseon Dynasty and Qing Dynasty ,and feel the social life and political survival of the Joseon Tongsa group.