In order to verify the application feasibility of RTV566 adhesive in space infrared cryogenic lens, the low temperature mechanical properties of RTV566 are tested, and the low temperature surface shapes of the experimental lens based on RTV566 are tested and studied. Firstly, RTV566 adhesive tensile test samples are designed and manufactured. And the bonding strength with germanium and titanium alloy，as well as the elastic modulus of the adhesive are obtained through static tensile test. Then the cryogenic lens test sample is designed and put into production. RTV566 adhesive is used to bond the lens into the frame, and a flexible structure is designed around the adhesive surface of the lens frame. The low temperature surface shapes of the lens are tested by ZYGO interferometer. The tensile test results show that the elastic modulus of the adhesive almost does not change from room temperature to 180 K, and the average value approximates to 6 MPa.The shear and tensile strength almost do not change from room temperature to 200 K, but increase at 180 K. The test results show that the surface shape of the lens almost does not change from room temperature to 200 K, whose accuracy is better than 1/30λ(λ=0.6328m).It indicates that the flexure structure and RTV566 adhesive reduce thermal stress, and ensure the surface shape of the lens. The research in this paper shows that RTV566 adhesive can be used in the support structure of space infrared cryogenic lens at 200 K and above.