Automated and intelligent construction machines are very important in for unmanned disaster response. One of the tasks involved in this is embankment construction. Usually, this conducted by teleoperation of a backhoe construction machine by one operator. Meanwhile, another operator controls an external camera which presents a visualization of the machine and the construction environment to the construction machine operator. In this paper, we propose a method for automatic control of the external camera based on the requirement specifications of the construction machine operator for unmanned embankment construction. This method consists of two parts: first, in order to present the desired visualization to the construction machine operator, the requirement specifications are extracted through video analysis at actual unmanned construction sites, and through interviews with construction machine operator. Next, an automatic external camera control method based on these requirement specifications is developed. In order to evaluate the effectiveness of the proposed method, it is necessary to compare the satisfaction/dissatisfaction of the videos from the backhoe operator's point of view. Therefore, we conducted a comparative experiment with camera control that satisfied and did not satisfy the requirement specifications. The superiority of the proposed method is shown by questionnaire evaluation using the proposed method.