Abstract: In order to study the action characteristics of high-voltage electrical pulse （ＨＶＥＰ）, an experimental system was developed and some concrete samples were made, the distribution and extension characteristics of cracks under non-stress were studied. Results show that HVEP has a positive influence on producing cracks in samples. After the action of HVEP, the crack network appears on the concrete samples, the number of main cracks is between 2 to 4, and the length is 25 cm to 32 cm. The cracks start from the hole of samples and the generative process of cracks can be divided into four stages, stress accumulation, slow development, rapid development and failure stage. The shock wave produced by liquid-electric effect of HVEP has a major role on fracturing samples, and the water-wedge effect can also promote the coal fracturing. After the action of HVEP, the flow degree of methane is improved, so the technology can encourage the exploitation of coalbed methane.