The invention discloses three-dimensional measuring equipment for submarine pipelines, which comprises a main bracket, a hydraulic clamping mechanism symmetrically disposed on the main bracket, a concentric positioning device, an axial displacement mechanism and a circumferential rotation mechanism. The main bracket is composed of a guide rod used for connecting a front support with a rear support. The hydraulic clamping mechanism is composed of oil cylinders arranged on the front and rear supports. The oil cylinders are connected with clamping claws. The concentric positioning device comprises a fixed seat fixed on the front and rear supports, and the fixed seat is internally provided with a screw. The screw is provided with a support rod. The axial displacement mechanism comprises an upper motor fixed on the front support, a rolling bearing installed at the upper part of the rear support, and a second semi-circular frame structure arranged between the front and rear supports. The circumferential rotation mechanism comprises a lower motor arranged on the second semi-circular frame structure, and a plurality of rollers connected with the second semi-circular frame structure. By means of the three-dimensional measuring equipment, a bent submarine pipeline or other heavily deformed/damaged submarine pipelines can still be accurately measured. Therefore, the one-shot success rate of the repair job is improved.