The measurement of gravitational acceleration plays a very important role， which is not only reflected in the basic research fields of metrology science， earthquake prevention and mitigation， but also in the practical application fields of pressure， force measurement， weighing instrument， geodesy and other professional fields. From 2016 to 2020， China National Institute of Metrology undertook and implemented the project of "Gravity Metrology Special Service". The project team went to Tibet， Xinjiang， Hong Kong and other regions， successfully completed the transmission of gravity acceleration in more than 50 stations， and initially established the National Gravity Metrology Reference Network. In the future， the team plans to further improve the National Gravimetric Reference Network.