Abstract: With the gradual exploitation of the global natural resources,many countries pay more attention to the coalbed methane(CBM) resources and invest to develop the relative new technologies and stimulation measures.It is an important supporting measure for enhancing the CBM recovery rate and safe coal extraction to master the de-tail CBM conditions in coalbed through the subhorizontal drilling in-situ exploring.Furthermore,the key of it is to realize the downhole hydraulic seal.This paper creates a new-type downhole hydraulic packer that can satisfy this requirement conveniently and quickly.The indoor experiment and in-situ experiment show that this packer can be applied in engineering practice.