In the process of continuous development ofthe company, in order to gradually pay attention to improving the productionconversion rate, realize automatic control in the production process, reducethe quantity of manual samples, reduce the risk of sampling operation,etc. At the same time, real-time monitoring,control product indicators real-time regulation to control productioncosts; The on-line analysis instrumenthas remarkable effect, which ensures accuracy and enhances timeliness comparedwith traditional manual sampling analysis. This paper will discuss the selection of different online monitoringschemes of key indicators under dangerous working conditions from the keyproject in the park.