Traditional surveying and mapping pay much attention to “accuracy”, but ignore the “speed”. Modern emergency mapping needs to be “speedy and accurate”. If traditional mapping techniques are used, it will consume a lot of time, which will affect the timeliness of emergency response. A tethered UAVs can collect high-quality data and realize real-time long-term video monitoring. This paper introduces the application status, characteristic advantages, and application scenarios of the tethered UAVs. And a kind of experience and method for using tethered UAVs to collect high quality image data and video data for producing surveying and mapping data products and identifying video targets through Darknet deep learning framework is proposed. Based on many simulation experiments and practical applications, the authors hold that this method is effective in providing timely and effective surveying and mapping guarantee for disaster relief and rescue.