The invention discloses a submersible pump guide vane design method, a submersible pump and a design device. The submersible pump guide vane design method comprises the steps of obtaining the preset working condition lift H, the preset working condition rotating speed n and the preset impeller diameter D of a submersible pump, calculating an inlet attack angle delta beta and an extrusion coefficient psi of the guide vane according to a preset formula. Therefore, the inlet attack angle delta beta and the displacement coefficient psi of the guide vane can be optimally designed by adopting an accurate formula design method. The design reasonability of the impeller is improved. The hydraulic impact loss of the guide vanes is reduced. The stability of the effluent liquid flow state is greatly improved. The mutual matching of the sizes of hydraulic components can be better ensured. The calculation is more accurate. The theoretical design is more consistent with an actual model. The application and programming of a computer are more facilitated. Therefore, the operation stability, high efficiency and economical efficiency of the submersible pump are improved to a certain extent.