The invention discloses a picosecond pulse laser cutting preparation method for a grid-control traveling wave tube grid mesh. The method comprises the following steps of performing cleaning, hydrogen burning and annealing on a grid mesh material, then pressing the grid mesh material through a die on a punching machine to form a spherical grid mesh blank with high curvature radius precision, performing destressing hydrogen burning on the blank to eliminate stress during processing to guarantee the stability of the curvature radius of a spherical cap of a grid mesh, and finally cutting the grid mesh by adopting picosecond pulse laser of an optimized technology to prepare the grid-control traveling wave tube grid mesh with high size precision and high consistency. According to the preparation method for the grid mesh of a grid-control traveling wave tube, specific technical parameters of picosecond laser cutting are screened through a large number of experiments, the operability is high, the technical design is reasonable, and the application range is large; the prepared grid mesh is high in size precision, high in consistency, high in yield and high in reliability and has an important application value; the shortcoming of an existing electric spark grid mesh processing technology can be effectively overcome.