A combined degassing method for a high-viscosity pure-chitosan spinning solution, characterized by comprising the following steps of: step 1, thoroughly dissolving the spinning solution in a dissolution vessel for subsequent use, the viscosity thereof reaching 450,000-500,000 mpa·s; step 2, delivering the spinning solution in step 1 to the feed port of a degassing vessel from the dissolution vessel through a filter under the action of compressed air as power; step 3, in the degassing vessel, under the conditions of vacuumizing and maintaining the inner pressure of the degassing vessel to be 500-3,000 Pa, performing continuous treatment on the spinning solution in step 2 by a combined degassing process integrating separation, film-scraping, lifting and shear, specifically comprising: (a) high-pressure separation shear: forcing the spinning solution in step 2 which is delivered to the feed port of the degassing vessel under the power of compressed air, to pass through 0.5 - 5 mm discharge holes distributed at the bottom of an annular feed pipe above the umbrella-shaped diffusion plate; (b) film-scraping shear: enabling the spinning solution from step (a) to drop onto an umbrella-shaped diffusion plate in the degassing vessel, flow from the inner edge to the outer edge of the umbrella-shaped diffusion plate, and drop to the bottom of the degassing vessel when flowing to the outer edge of the umbrella-shaped diffusion plate; (c) lifting separation shear and film-scraping shear: lifting the spinning solution at the bottom of the degassing vessel in step (b) up to the inner cavity of an inner cylinder body which is located above the umbrella-shaped diffusion plate via a stirring shaft with a screw propeller, enabling the solution to drop onto the umbrella-shaped diffusion plate through 0.5 - 5 mm liquid outlet holes and then drop to the bottom of the degassing vessel from the umbrella-shaped diffusion plate; repeating step (c); step (a), (b) and (c) being completed in the degassing vessel; and step 4, sampling the spinning solution in step 3 at a sampling port for the detection of degassing degree, finishing the degassing operation if the detection result is eligible, otherwise repeating step 3 until the detection result is eligible. step 1, thoroughly dissolving the spinning solution in a dissolution vessel for subsequent use, the viscosity thereof reaching 450,000-500,000 mpa·s; step 2, delivering the spinning solution in step 1 to the feed port of a degassing vessel from the dissolution vessel through a filter under the action of compressed air as power; step 3, in the degassing vessel, under the conditions of vacuumizing and maintaining the inner pressure of the degassing vessel to be 500-3,000 Pa, performing continuous treatment on the spinning solution in step 2 by a combined degassing process integrating separation, film-scraping, lifting and shear, specifically comprising: (a) high-pressure separation shear: forcing the spinning solution in step 2 which is delivered to the feed port of the degassing vessel under the power of compressed air, to pass through 0.5 - 5 mm discharge holes distributed at the bottom of an annular feed pipe above the umbrella-shaped diffusion plate; (b) film-scraping shear: enabling the spinning solution from step (a) to drop onto an umbrella-shaped diffusion plate in the degassing vessel, flow from the inner edge to the outer edge of the umbrella-shaped diffusion plate, and drop to the bottom of the degassing vessel when flowing to the outer edge of the umbrella-shaped diffusion plate; (c) lifting separation shear and film-scraping shear: lifting the spinning solution at the bottom of the degassing vessel in step (b) up to the inner cavity of an inner cylinder body which is located above the umbrella-shaped diffusion plate via a stirring shaft with a screw propeller, enabling the solution to drop onto the umbrella-shaped diffusion plate through 0.5 - 5 mm liquid outlet holes and then drop to the bottom of the degassing vessel from the umbrella-shaped diffusion plate; repeating step (c); step (a), (b) and (c) being completed in the degassing vessel; and (a) high-pressure separation shear: forcing the spinning solution in step 2 which is delivered to the feed port of the degassing vessel under the power of compressed air, to pass through 0.5 - 5 mm discharge holes distributed at the bottom of an annular feed pipe above the umbrella-shaped diffusion plate; (b) film-scraping shear: enabling the spinning solution from step (a) to drop onto an umbrella-shaped diffusion plate in the degassing vessel, flow from the inner edge to the outer edge of the umbrella-shaped diffusion plate, and drop to the bottom of the degassing vessel when flowing to the outer edge of the umbrella-shaped diffusion plate; (c) lifting separation shear and film-scraping shear: lifting the spinning solution at the bottom of the degassing vessel in step (b) up to the inner cavity of an inner cylinder body which is located above the umbrella-shaped diffusion plate via a stirring shaft with a screw propeller, enabling the solution to drop onto the umbrella-shaped diffusion plate through 0.5 - 5 mm liquid outlet holes and then drop to the bottom of the degassing vessel from the umbrella-shaped diffusion plate; step 4, sampling the spinning solution in step 3 at a sampling port for the detection of degassing degree, finishing the degassing operation if the detection result is eligible, otherwise repeating step 3 until the detection result is eligible.