The utility model discloses a sodium alginate microsphere preparation device. The device comprises an air pressure counting display screen, a rate button, a microsphere gun head, a ventilation hose, amovable iron clamp, an infrared sensor, a motor and an air pump, a power switch is mounted on one side of the air pressure counting display screen; a magnetic stirrer switch is mounted on one side, far away from the air pressure counting display screen, of the power switch; the speed button is fixed to one side of a magnetic stirrer switch, a receiver is installed on the side, away from the magnetic stirrer switch, of the air pressure counting display screen, the microsphere gun head is installed above the receiver, and a dripper is fixed to the side, away from the receiver, of the microsphere gun head. The sodium alginate microsphere preparation device is a simple device, integrates particle size control and automatic forming, greatly reduces the labor cost, can provide a stable flowingspeed under constant pressure, obtains microspheres with uniform particle sizes, and provides a basis for investigating the catalytic effect of the microspheres embedded with a catalyst.