In the present work, influence of silane solution concentration on mechanical, tribological and morphological properties of Corn Stalk Fiber (CSF) reinforced polymer composites was investigated. Experimental results showed that the silane-treated CSF reinforced polymer composite (CMS) exhibited a promising property of low density. Silane solution treatments of the CSF could effectively reduce the water absorption and apparent porosity of the polymer composite system. The silane-treated CSF could not effectively improve the friction performance, but could significantly improve the wear rate of the polymer composites. Especially, the sum wear rate of 5% silane-treated CSF reinforced composite (5% CMS) decreased by 22.8% from 4.792 × 10−7 cm3(N⋅m)−1 to 3.699 × 10−7 cm3(N⋅m)−1 compared with that of the raw CSF reinforced composite (CMU), showing the best wear resistant behavior. Worn surfaces were examined by Scanning Electron Microscopy and the results revealed that the silane-treated CSF was conducive to the formation of secondary plateaus on the polymer composite surface, which could obviously improve the tribological and morphological properties. •Corn stalk fibers were treated by the silane with the aim of develop bio-polymer composites.•The effect of surface treatment on tribological properties of the composites is confirmed.•Silane-treated corn stalk fibers were more effective in improving tribological properties.•Silane-treated corn stalk fibers were attributed to secondary plateaus on the worn surface.