Abstract: Span is one of the most important effective parameters of underground geotechnical engineering stability.Columns or piers structures are used in previous longspan roadway to reduce the roadway span and guarantee its stability,and these methods above affect the roadway' function seriously.Based on the mechanical analysis of the beam bridge and suspension bridge,we investigated the mechanism of reducing span and proposed the ideas of using deep long bolt(cable) to reduce span in underground works.The application has proven that the method has notable results for improving the deep long-span underground geotechnical stability.