Abstract: Lithospheric thickness is one of most important parameters to evaluate the earthquake evidence and dynamic mechanism of Tibetan plateau hot flow moving eastward.This paper obtains the stacking S receiver functions of 51 permanent broad-band stations and 211 teleseismic events records with the method of S receiver functions in Sichuan region,we get the depth distribution of the Moho and LAB through transformation of the depth in this region.The main results of the research are as follows:the Moho depth ranges from 40 to 72km in Sichuan region,it becomes thinner from eastern Tibet to Sichuan Basin,the thickest crust is about 72km,located in Yajiang region,the thinnest crust is about 40km,located in Xichong region,the average depth ranges from 52 to 68km beneath the Songpan-Ganze fold and Sichuan-Yunnan terrane,the crustal thickness is estimated to be 55～60km beneath western Longmenshan fault system and about 40km beneath Sichuan Basin，forming a step of 10～15km.the LAB depth ranges from 100 to 180km,western Sichuan Basin is found to be surrounded by a thinner lithosphere,the depth ranges from 100 to 130km beneath the basin boundary as thick as to from 140 to 180km,the thickest lithosphere is about 180km near X fault system, appearing as one depression and two uplifts,the thinnest lithosphere ranges from 100 to 120km beneath western Longmenshan fault system and northwestern Sichuan Basin,at the same time,the lithosphere thickness near Huamashi ranges from 100 to 120km.The last dynamic model of this paper is as follows:it is proved that a eastward preferential hot asthenosphere flow from Tibetan plateau is resisted by the cold thick rigid Sichuan Basin with Seismic evidence,thus branching into a northeastward and a southeastward one.