As a new convenient and faster transportation mode, the high-speed railway (HSR) construction and operation will make great impacts on the transportation condition, economic growth and human being’s working and living conditions in areas along the railway. The accessibility level will be promoted and the socio-economic linkage will be strengthened which are the most basic and direct impacts of HSR. Taking Henan as an example, the evolution of accessibility and spatial economic linkage among the 12 cities along the railway are probed before and behind the construction of HSR. The impact of "four vertical and four horizontal" HSR network all through the country on the inter-provincial accessibility and economic linkage of cities along the rail in Henan are also analyzed deeply. Results show that: 1) the travel time among cities along the rail will be greatly reduced under the construction of HSR from Xuzhou to Lanzhou and from Beijing to Guangzhou, and the economic region within 2 h will be formed basically. The pattern of "one vertical and one horizontal HSRs" constitutes the main channel of economic linkage, and the main directions of economic linage among cities in Henan will be formed along the railway. The marginalized condition of border cities along the railway will be reversed and the location disadvantage will be improved by the promotion of accessibility among the cities along the railway in Henan. 2) The interprovincial accessibility will have been improved under the network of "four vertical and four horizontal HSRs", and the quantity of inter-provincial economic linkage of cities mainly concentrates on the Changjiang River Delta, South China and the Bohai Sea Ring. The intensity of inter-provincial economic linkage is still very low among the cities along the railway and northeastern, northwestern and southwestern China, and the main linkage axis has not been formed. With the comparison of internal and external provincial accessibility and strength of economic linkage before and behind the completion of high-speed railway network, the necessity and significance of HSR are objectively demonstrated. The spatial orientation of regional economic development is identified clearly which is not only in favor of coordinating the contact and cooperation within zones or inter-zones, but also in favor of providing some references for the generation of regional development strategies.