During the construction of 99 000 m3 Type B cargo tank of Very Large Ethane Carrier (VLEC), 304L stainless steel studs were welded on the 5Ni cargo tank surface by drawn arc stud welding with ceramic ferrule, for fixing the insulation layer of cargo containment system. Performance of stud welding joint of 5Ni steel was analyzed by process test, appearance inspection, bend test, tension test, torque test, macroscopic structure inspection, hardness test and fatigue test. The results show that when the welding parameters were set to current intensity 800 A, welding time 0.3 s, protrusion 4 mm and lift 1.8 mm, the welding joints with regular and complete shape can be obtained, the performance can meet the design requirements.