A medical intelligent alleviating-pain machine. It comprised, oxygen source, laughing gas source, gaspath control module, respiration loop, CO2 absorber; the oxygen source and the laughing gas sourceare linked with two inlets of the gaspath control module, the outlet for mixed gases of the the gaspath control module and the exhalant gas inlet of patients will link with the respiration loop by pipes. The exhalant gas outlet of patients in the module will link with CO2 absorber, the useful gases after absorbing will return to the path for mixed gases by corresponding inlets; electronic controldevice, electrode sensor and stimulator will link with corresponding ports of the controal device, the control device adjusts the ratio of oxygen to laughing gas, and controls the transmisstion of the mixed gases to the respiration loop.