The utility model discloses a secondary layered splitting grouting device suitable for collapsible loess. Two ends of an expansion pipe of the device are respectively sleeved on a steel pipe sleeve toform an expansion assembly; one end of the slurry inlet pipe is open, the other end of the slurry inlet pipe is closed, the middle of the slurry inlet pipe sleeves axis holes of the steel pipe sleeves of the two expansion assemblies, and slurry outlet holes are evenly distributed in a pipe body, located between the two expansion assemblies, of the slurry inlet pipe; the inflation steel pipe comprises an inflation section and a deflation section which are located at the two ends, and two connecting sections located between the two ends. One end of the inflation section and one end of the deflation section are in butt joint with the eccentric hole of the steel pipe sleeve close to the opening end of the slurry inlet pipe and are communicated with the interior of the expansion assembly wherethe steel pipe sleeve is located; the two ends of the connecting section are connected to the eccentric holes of the steel pipe sleeve between the two expansion assemblies respectively and communicated with the interiors of the two expansion assemblies. According to the utility model, the effect of reinforcing a soil body can be effectively achieved, the directionality of slurry splitting can beensured, and the purpose of layered splitting and the effect of layered reinforcement can also be achieved.