Abstract: A printed circuit board with a lateral metallization groove and a processing method thereof, relates to the field of printed circuit boards with lateral metallization grooves, processing technologies thereof and batch processing methods. The processing method includes the following steps: step S01, drilling and milling grooves; step S02, performing metallization treatment; step S03, laying an outer layer circuit; step S04, performing pattern plating; step S05, performing first milling grooves; step S06, etching an outer layer; step S07, performing surface treatment after performing solder resist printing and character printing; step S08, forming to mill off connections of a processing side; step S09, performing second milling grooves to form a through groove. The present disclosure can implement: a long side of the printed circuit board can be directly connected with the ground wire rather than independently installing the ground wire; a small space is occupied and conveniently replacement.