Abstract: Leveling is always an important method to obtain precise elevation difference of ground points,but its slow measurement speed and low working efficiency are also difficult problems anound the world.In order to improve the speed and efficiency of leveling,the concept,structure,principle and method of a new high-speed bilateral observation digital level & staff are presented in this paper.Firstly,the unitized configuration design of level and staff is used so that the three-point interactive configuration in traditional leveling is changed into two-point interactive configuration to improve the station setting speed and terrain adaptability of level & staff.Secondly,the principle of dual measurement is invented in which the unidirectional and single system observation of the traditional leveling is changed into bilateral (double) and dual system observation to improve the accuracy and reliability of leveling.Furtherly,the orthogonal two-leg bracket and L type bubble level are designed and used to improve the station setting speed of the level & staff.The theoretical analysis and preliminary practice show that the speed and efficiency of leveling can be raised by more than one times by using the new high-speed bilateral observation digital level & staff which is the fastest,the most intelligent electronic leveling system in the world nowadays.The invention of the new high-speed bilateral observation digital level & staff,will have a tremendous and overturning impact on the global geodetic survey and engineering survey,and will open a new era of the popularity of electronic level in human society.

Key words: leveling, high-speed bilateral observation digital level & staff, new invention, design and practice