The utility model provides a spud leg coupling device is installation stage's rain -proof auxiliary device at sea which characterized in that: include: installing and geting in touch at the rain lintel of spud leg coupling device surface, the several of installing on the rain lintel, wherein, the rain lintel is installed on the settlement position of spud leg coupling device, the outer fringe of rain lintel is less than the axis of spud leg coupling device slightly, and forms the contained angle. The utility model discloses in the land fabrication stage, just install on spud leg coupling device surface, not only play the effect of rain lintel, and, can prevent effectively that the rainwater from flowing into the welding bead along spud leg coupling device surface, reached the marine installation stage of spud leg coupling device, requirement that the rain -proof was prevent wind, was constructed in succession, simultaneously, showing the welding environment that has improved the spud leg coupling device, avoiding the construction environment airtight, oppressive unfavorable condition appears, has extended construction space, has promoted the efficiency of construction.