Abstract: Using dual plugs or not,it is dangerous to build the pressure and over displacing in cementing or using small diameter drillstem to drilling slurry plug.Liner inner pipe cementing has solved the problems which using liner hanger with dual action choke ring assembly and connecting inner pipe under center pipe of liner hanger which through choke.When cementing,slurry flow through inner pipe and return annular space of liner not contacting with inner wall of liner.After cementing and replacing mud,remain 200-300 m slurry in inner pipe then lift inner pipe above choke ring and circulating slurry.The application in site shows reliable result in cementing.