Lens capable of rotatably adjusting light-emitting angle, optical system and implementation method thereof

The invention discloses a lens capable of rotatably adjusting a light-emitting angle, which comprises a lens body, a plurality of lens rings are arranged on the lens body at equal intervals from inside to outside, each lens ring comprises a plurality of first lens parts and second lens parts which are alternately arranged, and the light-emitting angles of the first lens parts and the second lens parts are different. The first lens parts and the second lens parts on the two adjacent lens rings are arranged in a staggered manner; the invention further discloses an optical system capable of rotatably adjusting the light emitting angle and an implementation method of the optical system capable of rotatably adjusting the light emitting angle. The lens body is matched with the light source plate, the lens body is rotated, the positions, corresponding to the lamp bead sets on the light source plate, of the first lens part and the second lens part are adjusted, and the light emitting angle of the whole lamp is adjust