With an aim to strengthen the ability and stability of the abrasive water jet machining, the magnetic field assisted micro abrasive water jet machining system was designed.This system was composed of multiaxis motion device,magnetic field generating device, pneumohydraulic intensifier,micro abrasive supply device and its control system.The pneumohydraulic intensifier of micro abrasive water jet was used of the type of gas liquid intensifier.The premixed device was used as the abrasive supply device.The ANSYS software was used to optimize the distribution of magnetic field, so that the uniform distribution of the magnetic field intensity was obtained.The programmable logical controller (PLC)was as the key control unitin system to controlin integration the nozzle movement and switch of the magnetic field generating device, the pneumohydraulic intensifier and the abrasive supplier.The online controland operation of the magnetic field assisted micro abrasive water jet machining system are realized by the design of the humancomputer interaction interface(HCII). 