To solve the problem of drying-up，the artificial excitation drainage observation and frequency conversion with steady flow pumping by submersible pump have been developed in the Liaogu-1 well． This paper analyzes the gas observation data from three kinds of water in taking patterns，including self-flow，artificial excitation drainage and frequency conversion with steady flow pumping by submersible pump． The results reveal that the gas observation dynamic characteristics by frequency conversion with steady flow pumping by submersible pump is basically consistent with by self-flow． But compared with self-flow，there were visible changes by artificial excitation drainage．