A finishing processing technique comprises the following steps that A, a no-dead-corner magnetic field is constructed, specifically, at least one pair of magnets is mounted on a rotary plate, a first motor is mounted on a sliding plate, one end of the sliding plate is in transmission connection with a second motor, the second motor can drive the sliding plate to slide transversely and horizontally, and the rotary plate is mounted on the first motor; B, machining stations with the interval being adjustable are constructed, specifically, a machining box is provided for the position above the magnetic rotary plate and mounted on a first liftable supporting table; C, a magnetic field test is conducted, specifically, a magnetic abrasive is added into a machining cavity, grinding liquid is pumped into the machining cavity, the magnetic abrasive is soaked in the grinding liquid, and the first motor is started to drive the magnetic rotary plate to rotate, so that the magnetic field is formed and can be adjusted through ascending and descending of the first supporting table; and D, magnetic grinding is conducted, specifically, a to-be-machined part is put into the machining cavity, and the second motor is started and drives the sliding plate to transversely slide back and forth, so that the magnetic field is distributed movably, and the part is subjected to finishing processing by colliding the part surface with the magnetic abrasive.