The Precursor Observation Network of China has experienced three main stages: analogue observation stage，ninth“Five Year Plan”digital stage and tenth“Five Year Plan” network stage． Each stage has a different observation system，and this increases the complexity of the running of the Precursor Observation Network． From 2010，CEA decided to integrate these different observation systems． The main content of this integration includes instrument and computer network transforming in stations， software upgrading， and migration of historical precursor observation data into the current database system in order to reach a uniform platform of data collection，storage，exchange，management and service． This paper analyses the status and main problems of the Precursor Observation Network before integration and introduces the main content and technical key points of integration and the results achieved．