The invention discloses a method for coating an antireflection film on the inner wall and outer wall of the outer tube of an all-glass vacuum solar energy heat-collecting tube, comprising the following steps: 1) preparing SiO2 sol; 2) preparing TiO2 sol; 3) coating a layer of SiO2 film on the outer tube of the solar energy heat-collecting tube by a pulling method; and 4) adopting the same coatingfilm condition and method as in step 3), and continuously coating a layer of TiO2 film on the outer tube processed in step 3). In the invention, a sol-gel method is used to coat the antireflection film on the inner wall and outer wall of the outer tube of the all-glass vacuum solar energy heat-collecting tube, the transmissivity of the outer tube after being coated with the film is improved to 96-98% to ensure that solar energy heat absorbed by the surface of an inner tube can be increased by 6-8%, thus improving the heat gain of the whole all-glass vacuum solar energy heat-collecting tube, so as to achieve the purpose of improving the heat efficiency of the all-glass vacuum solar energy heat-collecting tube.