A display panel, a manufacturing method thereof and a display device are provided. The display panel comprises: a first substrate and a second substrate which are opposite to each other to form a cell through a sealant. A first sealant-blocking structure configured to prevent the sealant from extending toward an edge of the display panel is formed on the first substrate and/or the second substrate. The display panel effectively prevents the sealant from extending toward the edge of the display panel by forming the first sealant-blocking structure on an outside of the sealant, and hence achieves an ultra-narrow frame or unframed design.