It is half-automated double-edge welding machine, which operation process is as follows: first, the strip was inserted the welding die by manual, then push the double-button, the machine run auto cycle, including: heating device moving up-heating-the heating device return-vacuuming-the latitude die close-thimble inserting into strip-inside cooling-outside cooling-trimming-longitude die open-push out the strip with mandril, last, unloading the strip by manual. The characteristic of this welding machine is as follows: Good flatness welding surface and reliable strength of welding joint, automatic trimming, reliable quality, less work cycle time and high finished-product rate.