A spliced guardrail convenient to dismount and mount comprises a plurality of supporting components. Each supporting component comprises an arc-shaped coaming, a shaft sleeve and a shaft arranged at the lower end of each arc-shaped coaming, two supporting feet extending from the inner wall of each arc-shaped coaming, and first adjusting pieces mounted at the adjacent edge parts of the two supporting feet. The included angle of the two supporting feet and the radian of each arc-shaped coaming can be adjusted by stirring the first adjusting pieces. The multiple supporting components are sequentially spliced into one guardrail capable of being matched with the shape of an internally-arranged product, and the adjacent supporting components are movably connected with each other through the corresponding shafts and shaft sleeves. The supporting components and the adjusting pieces are standard components, can be spliced to assemble guardrails in different shapes, assembly is rapid and convenient, dismounting is convenient, and storage and transporting are convenient. The spliced guardrail serves as a flower and plant guardrail, a product exhibition rail and a guardrail of a transparent flexible fish tank.