The invention discloses a method for improving performance of an intelligent relay and a shell structure. Support columns and connection columns are arranged between a cover plate and a casing, one ends of the support columns are connected with the casing, one ends of the connection columns are connected with the cover plate, and the other ends of the connection columns pass through a circuit module and are fixed on the circuit module, and are connected with the support columns, thereby forming resonance among the cover plate, the circuit module and the casing, and improving anti-vibration performance of the intelligent relay; the shell structure includes a mounting rack, a second module interface placing opening is arranged on the mounting rack, the mounting rack is connected with the casing, one side of the casing is provided with the support columns, the support columns are connected with the connection columns, the connection columns are connected with the cover plate, and a first module interface placing opening is arranged on the cover plate; the height of a cross section of the cover plate is smaller than that of a cross section of the casing; and the back of the casing is a cambered surface. The shell structure provided by the invention has the characteristics of high anti-vibration performance, good heat dissipation effect and strong anti-pressure capability, and in addition, also has the characteristics of being reasonable in design and convenient to mount.