A manufacturing method of a splicing display panel and the splicing display panel are provided. Front surfaces of backplates are encapsulated to form first encapsulation layers. Then, at least two backplates are fixed on a transparent substrate to make grooves be formed between lateral surfaces of two adjacent backplates and the transparent substrate. Next, second encapsulation layers are formed in the grooves to obtain an encapsulation semi-finished product. Finally, a third encapsulation layer is formed on a peripheral side of the encapsulation semi-finished product, thereby obtaining the splicing display panel. Technical problems that encapsulation of lateral surfaces of the display panel is difficult and seams of the splicing display panel are obvious can be solved.