The invention provides a working device and method for gas pipe type hydraulic connecting of a submarine pipeline. The working device and method are applied to connecting and repairing of the submarine pipeline. The working device for connecting of the submarine pipeline comprises three sets of independent hydraulic propelling systems, and underwater clamping and pre-manufacturing of the submarinepipeline and underwater butt-joint work of the submarine pipeline and a submarine pipeline restorer are implemented according to the hydraulic drive fine adjustment and centring function of a horizontal gas pipe balancer and the submarine pipeline restorer and a vertical limiter and a hydraulic centring device. Horizontal multi-stage gas pipes are adopted by the gas pipe balancer, and the functions of suspension balance and dynamic load adjustment are achieved by adjusting the volume ratio of micro-positive pressure gas in all stages of gas pipes and seawater. The submarine pipeline restorercompletes underwater butt joint of two pipe segments of the submarine pipeline through axial inner puling connecting work. A vertical thick-wall barrel is adopted by the limiter, and the vertical limiting function during axial propelling of the hydraulic centring device is achieved according to a spline sliding way between a limiting barrel and a limiting plunger. A connecting anticorrosion devicecomprises a butt-joint anticorrosion device and a guide anticorrosion device, and a submarine pipeline connector is protected against sea mud corrosion.