Abstract: Aiming to meet the technical requirements of rapid nondestructive testing of cracks in riser girth weld area, this paper designed an array probe of AC electromagnetic field based on the adaptive testing technology of AC electromagnetic field. A rapid detection system for cracks in riser girth weld was developed, and rapid detection experiments for cracks in riser specimens' welds and heat-affected zones were carried out. The results show that the rapid detection system of riser girth welds based on AC electromagnetic field can realize the rapid detection of riser girth welds and cracks of 1. 0 mm deep in the heat-affected zone, which is of great significance to the safety detection and maintenance of riser.