After studies on the optical image system of micro-displacement measurement based on the laser triangulation measurement,the concept of slantwise magnification was put forward and its formula was proved.

For the first time, the influence of base plate and projecting angle on the formation of the jet has been considered By utilizing the one dimension quasi steady flow theory,the calculation formulas of the mass,moving direction and velocity are deduced for the jet that is formed in the colliding process of flyer plate against base plate under the condition of slant setting.

Analysis on the detection to project pile declivity ratio of the method of drilling core hole detecting the declivity;