The invention discloses a processing method for a wood guitar. The processing method comprises the following steps: A, selecting materials; B, drying; C, cutting; D, grinding a handle body and side plates; and E, grinding a panel. A grinding device is used to grind the panel, and the grinding device comprises a rack, and further comprises a fixing mechanism for fixing grinding balls, wherein an upper clamping plate and a lower clamping plate used for clamping the guitar panel are arranged on the rack; the upper clamping plate and the lower clamping plate are connected with a rotary shaft; the rotary shaft is connected with a drive mechanism; the grinding balls are arranged at the two sides of the guitar panel; and a first connecting rope is connected between each grinding ball and the rack. The step of grinding the panel comprises the following specific steps of: a, putting the guitar panel onto the rack, and clamping the guitar through the upper clamping plate and the lower clamping plate; b, fitting the grinding balls to the sides of the panel, and fixing the grinding balls by the fixing mechanism; and c, starting a drive mechanism for rotating the guitar panel, and grinding the guitar panel through the grinding balls. The invention aims to provide the processing method for the wood guitar, and the processing method solves the problem that manual guitar grinding operation is complex, and improves guitar production efficiency.