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).