The invention belongs to the technical field of the sensors and relates to a thermal convecting one-chip three-axial accelerating sensor. Basic principles of the invention are that air inside a sealed cavity body is inducted to do thermal convection through a heat-sensitive component, and an accelerating signal is transmitted through calculations. The invention comprises a packing cavity which is located on the surface of a heating wire temperature sensor and an etching cavity which is located under the surface of the heating wire temperature sensor. The packing cavity and the etching cavity are arranged in symmetry in four groups of sensors around center. The invention applies for a plurality of fields as automobile, game industry, aviation, ship navigation system, product for civilian use, military, and the like. The invention adopts thermal convection principles to test accelerating information, and has no mass block, and can work under high-g. The invention has impact resistance without adhesions or granules, low cost, low failure rate, high rate of good product, high sensibility, and strong anti-interference. Compared with original one-chip three-axial accelerating sensors of MEMSIC Company, a test for accelerating inside a three-dimensional space is available.