The invention relates to a support device for submarine seismograph placement based on rigid connection, and belongs to the field of submarine earthquake monitoring. The support device comprises a main body bracket, a chassis, side support rods, a side cover, anti-jamming vertical pipes, a submarine seismograph, a metal wire fusing device, a metal wire and ropes, wherein the main body bracket is formed by connectionin a welding manner; the chassis is located at the central position of the bottom of the main body bracket; the side support rods are evenly distributed around the main body bracketand form included angles being 60 degrees together with the bottom surface of the main body bracket; the anti-jamming vertical pipes are vertically placed around the submarine seismograph; the side cover is tapered, and is connected with the side support rods by bolts; the submarine seismograph is erected above the chassis, and fixed by the ropes; the metal wire fusing device is arranged above the submarine seismograph to serve as a release device of the submarine seismograph; and the ropes are used for fixing the submarine seismograph to the chassis. The support device is mainly applied to placement and recovery of the submarine seismograph, can effectively improve the ability of the submarine seismograph to resist impact, erosion and trawl, and has the ability to maintain the normal operation of the submarine seismograph.