A portable air extracting device includes a shell assembly and an electric air extracting pump. The shell assembly includes a top shell, a side shell and a bottom shell surrounding a fluid room. The bottom shell is provided with an external air-extracting hole. The external air-extracting hole connects the fluid room to a target space to be evacuated. The electric air extracting pump includes an intake nozzle and an outtake nozzle. In particular, the intake nozzle is misaligned with the external air-extracting hole.