Abstract: A new self-adapting control method of A1 pulsed- MIG welding was presented, and a meso-spray zone with a specified arc voltage bound is designed to control the droplet transfer in the meso-spray zone in spite of its characteristic of narrow scope and difficult manipulation.From the method, the arc current and voltage can be automatically controlled within the meso-spray zone by confirming the pulsed current in response to the arc voltage and also automatically meet the fluctuating of wire feed rate and arc length.For Aluminum wire of 1.6 mm diameter, the meso-spray zone based on the above control idea is confined within 14.5 -22 V and 30 -235 A, and the pulsed welding experiments companied with high speed photogragh are put into effect and show good control of meso-spray, the good weld appeararce and better prevention from producing welding defects.