Wavefront errors of the active deformable mirror are analyzed and experimentally studied.Based on the theoretical and experimental wavefront errors of the active deformable mirror, with key parameters gotten by the finite element method about compensating capabilities of the low-frequency errors for 300 mm aperture and 1926 mm radius of curvature,37-element spherical active deformable mirror, has been fabricated. The peak-valley value and root-mean-square are 0.545λ (λ, warelength) and 0.081λ before correction, while 0.239λ and 0.031λ are achieved after correction in experiments.The techniques and craftubrk, such as mirror surface machning and actuator tip cementation, were explored.