Abstract: Grouting is the very important method in the jointed rock mass reinforcement of underground engineering and has a board application in mining engineering, slope treatment, chamber supporting and so on. The sandstone containing two coplanar fissures was taken as an example, which was firstly treated to filling reinforcement with different cement materials and then conducted to indoor uniaxial compression test, to study the strength and failure characteristic of sandstone under the effect of filling reinforcement. The test results show that, the strength of sandstone samples containing two coplanar fissures has obvious degradation compared with that of intact sample, and the degradation range is between 18.68% and 36.99%. With the increase of the strength of filling material, both peak strength and the average modulus of sandstone present the gradually increasing feature. Filling material has a great influence on the fracture form of sandstone. As the strength of filling material is relatively low, the failure process of sandstone mainly manifests as the crack propagation from the pre-fissure tip. While the strength of filling material is relatively high, the pre-fissure tip propagation is effectively suppressed, and the fracture surfaces are mostly characterized by the arrangement through the pre-fissures. The research results could provide some necessary theory basis for the supporting design and disaster prevention of jointed rock mass in underground engineering.