Hot dip Zn-based alloy coated steel sheets are arc-weld in such a way that (a) a current waveform is a pulsed current waveform in which (i) a peak current and a base current alternate with each other at a pulse period of 1 ms to 50 ms and (ii) an average welding current is 100 A to 350 A and (b) an average welding voltage is 20 V to 35 V. Each of the hot dip Zn-based alloy coated steel sheets includes a coating layer that contains Zn as a main component and that contains Al at a concentration of 1.0% by mass to 22.0% by mass, and has a coating weight W of 15 g/m 2 to 250 g/m 2 [ Fig. 1 ]