Exhaust gas recirculation coller

The invention relates to an exhaust gas recirculation cooler. The exhaust gas recirculation cooler comprises a shell and a plurality of pocking mark radiating pipes arranged in the shell and distributed in an array mode, splayed grooves and protrusions are evenly arranged on the outer wall of each pocking mark radiating pipe, and the grooves and the protrusions are evenly distributed in the lengthdirection of a pipe body in two alternately-arranged combined unit modes; the first combination unit is that the unfolded ends of two splayed grooves are oppositely distributed, the whole first combination unit is in a rhombus shape, and a conical protrusion is arranged between the unfolded ends of the two splayed grooves; the second combination unit is that closed ends of two splayed grooves areoppositely distributed, the whole second combination unit is in an X-shape, and no conical protrusion is formed between the two grooves; and the protrusions on the two adjacent opposite pocking markradiating pipes are arrange