The invention belongs to the technical field of oil gas pipeline flowing fluid safety ensuring technologies and relates to a seabed oil gas transportation pipeline hydrate blockage detecting and blockage removing device. The detecting and blockage removing device comprises a heating system, a positioning system, a detecting system, a counterweight system and a shell. When hydrates begin to be deposited and gathered and block a pipeline, the device can send out blockage position information, the hydrates can be heated and decomposed, and dredging of the pipeline is facilitated. The device is provided with the counterweight system, adjustment can be conducted according to fluid, and therefore the device can be suitable for various kinds of fluid. The shell is provided with a hole channel, itcan be ensured that the device suspends in the fluid, and the device can run stably along with the fluid. In addition, due to the hole channel which is symmetric in all directions and is included inthe shell, it can be ensured that the fluid can flow in and flow out of the device without obstacles, and the oil gas transportation pipeline cannot be blocked. In addition, multiple devices differentin diameters can be practically manufactured to be used in cooperation according to functions. The device can be used cyclically, and the economical efficiency is improved.