Disclosed are an arched lighting device, an imaging system having same, and an imaging method. The lighting device comprises a housing having an arched structure and a plurality of LED light sources disposed on an inner wall of the housing. The housing is provided with a slot through-hole disposed in the lengthwise direction of the housing. The LED light sources are arranged in an array to form an LED light source array. The LED light source array comprises a plurality of LED light source row units arranged in the lengthwise direction of the housing. The luminous intensity and/or light color of each LED light source row unit can be independently adjusted. The arched lighting device of the present invention is provided with the LED array on an inner side of an arched surface, thus enabling objects under test to be illuminated from every angle within the range of 180 degrees. In addition, the luminous intensity and color of each LED can be independently controlled, so as to obtain the optimal light angle capable of covering circuit-board surfaces having various shapes, textures, and other different conditions.