The invention discloses a vacuum pumping device and belongs to the field of automobile braking assistance. An electromagnetic coil and a magnetic field controller are installed in a protection shell of the vacuum pumping device. A foot stand is fixed to the lower face of the outer face of the protection shell. The lower end of the foot stand is fixed to a vacuum tank. The electromagnetic coil is fixed to the lower face of the outer face of a negative-pressure shell. The lower end of the negative-pressure shell is fixed to the lower end in the protection shell. A pipe shaft type air outlet valve, a sealing ball or a sealing cone, a power spring and an induced-magnetism piston are installed in the negative-pressure shell. The lower end of the pipe shaft type air outlet valve penetrates a center hole in one end of the upper face of the negative-pressure shell and then penetrates the power spring and the induced-magnetism spring. The sealing ball or the sealing cone can be in cooperation with an inner cone face to seal or open an air pumping channel and an exhaust channel. The vacuum pumping device is compact in structure, small in size, high in power, high in dynamic, high in vacuum pumping efficiency and low in electric energy consumption.