Abstract: The stability of engineering rock mass is mainly controlled by the characteristics of joints.The extraction and analysis of rock mass joint information are of great significance to engineering design， geological engineering evaluation and construction safety. Aiming at the problems of a large workload， high labor intensity， high operational risk， and low efficiency in current rock joint information extraction， a technique for extracting regional rock joint information based on multi-rotor flight control platforms is proposed. The software and hardware components of the system are analyzed，the data processing flows of UAV aerial survey， three-dimensional virtual reconstruction of regional rock mass environment， and joint information extraction are discussed，besides that，three key technologies of multi-rotor UAV for joint rock mass data acquisition， virtual reconstruction of joint rock mass model based on aerial video， and extraction and analysis of joint information are analyzed and summarized.At the same time， the accuracy of the system is verified.Based on the investigation of joint and fissure of slope in Heigou mining area， the technical verification is carried out.The field test results show that the method of extracting joint information proposed in this paper has the advantages of simple operation and high accuracy， which provides a reference for rapid extraction of rock mass joint information.

Key words: joint information of rock mass, multi rotor UAV, field collection, virtual reconfiguration, joint information extraction