Abstract: Based on the analysis of the curre ntly-used welding technologies，a technological scheme of hot-cold double-wire SAW for the heavy-wall steel pipe is proposed here in the paper. Specifically the said scheme covers such a operation mode，i.e.，getting two welding wires with different thermal states simultaneously enter the SAW process by means of setting a metallurgical reaction molten pool so as to achieve both stable quality control and rapid enhancement of the productivity of the DH36-Z35 heavy-wall welded pipe. Relevant industrial experiment result shows that thanks to the above mentioned cold-hot double-wire SAW process，proper control of the low hot output and high metal deposition efficiency of the heavy-wall steel tube welding process are obtained，which is of reference value for enhancing the productivity of the heavy-wall（t≥50 mm） DH36-Z35 welded steel pipe.