The designed ultra-long airtank(DK7000)was introduced.In order to make the best of the existing coating production conditions and satisfied with the painting production and quality requirements for DK7000 airtank and all other varieties.The existent problems of coating production was effectively solved by optimized design of the coating technology process of DK7000 airtank,horizontal hanging,horizontal spray and inversion technology were applied,so that DK7000 airtank were producted very well.