An electrochemical multi component gas sensor for gas detection of NO

2

NH3

SO

2

and H2S is designed and fabricated.Room temperature ionic liquids with stable electrochemical properties

low saturated vapor pressure and good gas selectivity are selected as electrolytes for electrochemical gas sensors.Selective measurement of sensor to measured gas is realized

and the problems of the electrolyte of traditional electrochemical gas sensor is easy to dry and short service life are solved.An open and integrated electrolytic cell is designed as sensitive unit of the sensor

the minimized structure design of the multi-component electrochemical gas sens

or is realized. At the same time

the structure of the open eletrolytic cell is beneficial to the diffusion of the measured gas on electrode

and the response speed of the sensor is improved. The electrochemical workstation is used to analyze on performance of the sensor.The response time（τ90） of the sensor is less than 20 s

and the measurement precision is prior to ± 1. 5 % FS. Analysis results show that the designed multi-component electrochemical gas sensor has the characteristics of good gas selectivity

fast response and high measurement precision.