An electronic expansion valve, comprising: a valve body having a tubular shape, wherein the valve body comprises a main body section , an extension section and a step section connecting the main body section and the extension section , and an inner diameter of the main body section is greater than an inner diameter of the extension section ; a valve seat core having a tubular shape and having openings at two ends, wherein the valve seat core comprises a tubular body and a limiting step formed at one end of the tubular body , the tubular body penetrates through the extension section , the limiting step abuts against an inner wall of the step section and one end of the tubular body away from the limiting step extends out of the extension section ; and an air outlet pipe , which is sleeved in the extension section and abuts against an outer wall of the step section , and a groove is defined by an inner wall of the air outlet pipe , the extension section , and an outer wall of the tubular body in a surrounding mode and configured for accommodating a welding ring; characterized in that , the tubular body comprises a middle portion and an edge portion , the middle portion is located between the limiting step and the edge portion , and the middle portion forms an interference fit with the extension section ; and a length of the middle portion is less than a length of the extension section , and an outer diameter of the middle portion is greater than an outer diameter of the edge portion , so that a gap having an annular shape is defined between an inner wall of the extension section and an outer wall of the edge portion , and the gap communicates with the groove . a valve body having a tubular shape, wherein the valve body comprises a main body section , an extension section and a step section connecting the main body section and the extension section , and an inner diameter of the main body section is greater than an inner diameter of the extension section ; a valve seat core having a tubular shape and having openings at two ends, wherein the valve seat core comprises a tubular body and a limiting step formed at one end of the tubular body , the tubular body penetrates through the extension section , the limiting step abuts against an inner wall of the step section and one end of the tubular body away from the limiting step extends out of the extension section ; and an air outlet pipe , which is sleeved in the extension section and abuts against an outer wall of the step section , and a groove is defined by an inner wall of the air outlet pipe , the extension section , and an outer wall of the tubular body in a surrounding mode and configured for accommodating a welding ring; characterized in that , the tubular body comprises a middle portion and an edge portion , the middle portion is located between the limiting step and the edge portion , and the middle portion forms an interference fit with the extension section ; and a length of the middle portion is less than a length of the extension section , and an outer diameter of the middle portion is greater than an outer diameter of the edge portion , so that a gap having an annular shape is defined between an inner wall of the extension section and an outer wall of the edge portion , and the gap communicates with the groove . <EOS>