The invention provides a device and a method for testing shielding effectiveness of a curved surface electromagnetic shielding fabric. The device comprises a fabric fixing frame, a curved surface adjusting rod and an edge fixing device, wherein the fabric fixing frame comprises a main board and an auxiliary board, the main board and the auxiliary board are connected through a connecting rod, curved surface adjusting rods are arranged on the main board and the auxiliary board, and the edge fixing device comprises a pressing plate arranged on the main plate. The problem that the shielding effectiveness of the curved surface form electromagnetic shielding fabric cannot be tested currently is solved. An important basis is provided for design, production and evaluation of the electromagnetic shielding clothing and the shielding covers, and a theoretical foundation is laid for related research of the electromagnetic shielding fabric. The device is simple to operate, accurate in testing effect, low in cost, and is practical and novel.