629 nm spectral line can be obtained with the method using Fabry-Perot (F-P) etalon in He-Ne laser cavity. That spectral line is hard to realize by the traditional method, like coating film. The shifting of 629 nm line′s transmission window in F-P etalon is analyzed. In order to obtain a stable 629 nm output, the lower limit of the F-P etalon′s angle range is calculated. A new folding piezoelectric angle controller is presented, which can provide a wide angle range adjustment. A stable output 629 nm He-Ne laser is realized with a feedback control. The stable output light power reaches 80 μW approximately.