The rapid growth of the economic promotes the demand for mineral and energy resources in China, which is the reason that the drilling projects increase every year. Pipe sticking occurs frequently in the complex formations. Jar is often used to solve the pipe sticking accident in oil and gas drilling; however, in the small-caliber geological drilling, the jar could not work as usual, new kinds of jar are necessary to be designed. This paper introduces a hydraulic jar with spring-loaded valve, which was designed for serious pipe sticking in Ukraine, and this structure could not only ensure the work reliability, but also improve the efficiency of solving the pipe sticking by its high-frequency impact power. The mechanical while-drilling jar designed for the areas where pipe sticking often happens can make sticking unfreezing in first time to avoid the further accident and effectively save the time of failure treatment.