The utility model discloses a dissolving test device for a soluble bridge plug. The dissolving test device comprises a constant-temperature water bath tank, a lifting frame, a hose, an upper joint, asleeve nipple, a high-temperature heat tracing band, a lower joint and an adjustable sleeve bracket, the constant-temperature water bath box is fixedly mounted on the lifting frame table board; an outlet in the lower portion of the constant-temperature water bath box is connected with an upper connector through a hose, the upper connector is in threaded connection with one end of a casing pipe nipple, a lower connector is in threaded connection with the other end of the casing pipe nipple, the outer surface of the casing pipe nipple is wrapped with the high-temperature heat tracing band, and the casing pipe nipple is transversely arranged and fixed to a casing pipe support. According to the device, the solubility test can be carried out according to the to-be-applied well condition beforethe soluble bridge plug enters the well, and the solubility performance of the soluble bridge plug is mastered, so that the soluble bridge plug is guided to be accurately and efficiently used under different underground working conditions which are not easy to observe, and the problem that a test device capable of simulating the actual dissolution working condition of the soluble bridge plug on site does not exist at present is solved.