Research conclusions:Taking the Wuhan － Guabgzhou Passenger Dedicated Line as the engineering background，the different calculation methods for the tensile force of the geogrid were summarized． The plane finite element analysis model was established． The variation laws of the subgrade settlement，the load on the geogrid and the pile － soil stress ratio in process of subgrade filling were analyzed on consideration of the different geogrid modulus conditions．After the soil filling to a certain height，the increases of subgrade settlement，the load on the geogrid and pile － soil stress ratio became slow． The increase of geogrid modulus led to the obvious increase of the load on the geogrid． The use of reinforced cushion could effectively solve the problem of thestress concentration on the pile top problems and control the subgrade settlement．