An electronic expansion valve , comprising: a valve seat formed with a main valve cavity ; and a valve needle assembly comprising a valve needle sleeve provided inside the main valve cavity , wherein the valve needle sleeve is formed with a needle sleeve cavity and an end wall of the needle sleeve cavity is defined with a main valve port , the main valve port comprises: a first deflector hole section ; a second deflector hole section , wherein the first deflector hole section and the second deflector hole section being distributed along a direction towards an outside of the main valve port ; and a rectification hole section provided between the first deflector hole section and the second deflector hole section , wherein the rectification hole section being connected with the first deflector hole section , and wherein a hole diameter of the rectification hole section is larger than a hole diameter of the first deflector hole section , so as to form a step between the rectification hole section and an inner wall of the first deflector hole section , wherein the valve needle assembly further comprises a valve needle provided inside the valve needle sleeve , a tip portion of the valve needle is at least partially provided inside the main valve port , characterized in that, L represents a distance between an end face of the tip portion and a bottom wall of the needle sleeve cavity ; L 1 represents a length of the first deflector hole section ; L 2 represents a length of the rectification hole section ; and L 3 represents a length of the second deflector hole section , and L is not less than L 1 +L 2 +L 3 and not greater than 1.5(L 1 +L 2 +L 3 ). a valve seat formed with a main valve cavity ; and a valve needle assembly comprising a valve needle sleeve provided inside the main valve cavity , wherein the valve needle sleeve is formed with a needle sleeve cavity and an end wall of the needle sleeve cavity is defined with a main valve port , the main valve port comprises: a first deflector hole section ; a second deflector hole section , wherein the first deflector hole section and the second deflector hole section being distributed along a direction towards an outside of the main valve port ; and a rectification hole section provided between the first deflector hole section and the second deflector hole section , wherein the rectification hole section being connected with the first deflector hole section , and a first deflector hole section ; a second deflector hole section , wherein the first deflector hole section and the second deflector hole section being distributed along a direction towards an outside of the main valve port ; and a rectification hole section provided between the first deflector hole section and the second deflector hole section , wherein the rectification hole section being connected with the first deflector hole section , and wherein a hole diameter of the rectification hole section is larger than a hole diameter of the first deflector hole section , so as to form a step between the rectification hole section and an inner wall of the first deflector hole section , wherein the valve needle assembly further comprises a valve needle provided inside the valve needle sleeve , a tip portion of the valve needle is at least partially provided inside the main valve port , characterized in that, L represents a distance between an end face of the tip portion and a bottom wall of the needle sleeve cavity ; L 1 represents a length of the first deflector hole section ; L 2 represents a length of the rectification hole section ; and L 3 represents a length of the second deflector hole section , and L is not less than L 1 +L 2 +L 3 and not greater than 1.5(L 1 +L 2 +L 3 ). <EOS>